1

Isaac Newton Institute of Chile in Eastern Europe and Eurasia Casilla 8-9, Correo 9, Santiago, Chile e-Mail: [email protected] Web-address: www.ini.cl ͓S0002-7537͑95͒03301-4͔

The Isaac Newton Institute, ͑INI͒ for astronomical re- and luminosity functions ͑LFs͒ of the cluster Main Sequence search was founded in 1978 by the undersigned. The main ͑MS͒ for two fields extending from a region near the center office is located in the eastern outskirts of Santiago. Since of the cluster out to Ӎ 10 arcmin. The photometry of these 1992, it has expanded into several countries of the former fields produces a narrow MS extending down to VӍ27, Soviet Union in Eastern Europe and Eurasia. much deeper than any previous ground based study on this As of the year 2003, the Institute is composed of fifteen system and comparable to previous HST photometry. The V, Branches in nine countries ͑see figure on following page͒. V-I CMD also shows a deep white dwarf cooling sequence These are: Armenia ͑19͒, Bulgaria ͑28͒, Crimea ͑35͒, Kaza- locus, contaminated by many field stars and spurious objects. khstan ͑18͒, Kazan ͑12͒, Kiev ͑11͒, Moscow ͑23͒, Odessa We concentrate the present work on the analysis of the ͑35͒, Petersburg ͑33͒, Poland ͑13͒, Pushchino ͑23͒, Special MSLFs derived for two annuli at different radial distance Astrophysical Observatory, ‘‘SAO’’ ͑49͒, Tajikistan ͑9͒, from the center of the cluster. Evidence of a clear-cut corre- Uzbekistan ͑24͒ and Yugoslavia ͑23͒. The quantities in pa- lation between the slope of the observed LFs before reaching rentheses give the number of scientific staff, the grand total the turn-over, and the radial position of the observed fields of which is 355 members. inside the cluster area is found. They find that the LFs be- come flatter with decreasing radius ͑x Ӎ 0.15 for 1 arcmin 1. RESEARCH IN CHILE Ͻ R1 Ͻ 5.5 arcmin;xӍ 0.24 for 5.5 arcmin Ͻ R2 Ͻ 9.8 The primary research program of the Institute in Chile arcmin; core radius, rcϭ 0.05 arcmin), a trend that is continues to be observational studies of globular clusters in consistent with the interpretation of NGC 6397 as a dynami- the Galaxy and the Magellanic Clouds. In addition, a number cally relaxed system. This trend is also evident in the mass of open clusters have been observed. In this field around 200 function ͑2004, A&A, 425, 509-518͒. papers have been published. Besides the above named Branches, following the Con- 2. THE INI ARMENIAN BRANCH vention of Scientific Collaboration with the Rome Observa- The Isaac Newton Institute opened its Branch in Armenia tory of February 2000, Gonzalo Alcaino and Franklin Alva- in June 2000. The formal Agreement has been signed with rado are involved with Italian astronomers in several Prof. Edward Khachikian, at that time the Director of the research projects using data secured from telescopes in Byurakan Astrophysical Observatory of the Armenian Na- Chile. tional Academy of Sciences. CCD photometric analysis has now been completed by The staff of the Isaac Newton Institute Armenian Branch Gonzalo Alcaino, Franklin Alvarado, Guiseppe Bono and consists of 17 scientists: Hamlet Abrahamian, Smbat Bal- Gianni Marconi for the globular clusters NGC 1261, ayan, Kamo Gigoyan, Armen Gyulbudaghian, Lidia Eras- NGC 1851 and NGC 3201. The work is being prepared for tova, Susanna Hakopian, Haik Harutyunian, Rafik Kanda- submission. lyan, Arthur Karapetian, Tigran Magakian, Norair Melikian, As from 2004, a systematic program of CCD data reduc- Areg Mickaelian, Tigran Movsessian, Hripsime Na- tion obtained at La Silla and Las Campanas by Gonzalo Al- vasardyan, Arthur Nikoghossian, Elena Nikogossian, and caino and Franklin Alvarado is ongoing with Nikolai Samus Artashes Petrosian. The Resident Director of the INI Arme- and Alexei Mironov from INI-Moscow Branch. Around 50 nian Branch is Areg Mickaelian. stars clusters will compose the envisaged project in the forth- The Byurakan Astrophysical Observatory ͑BAO͒ is the coming years. main astronomical institution in Armenia and one of the G. Alcaino, F. Alvarado, A. Mironov and N. Samus are most important observatories of the Former Soviet Union. It now engaged in final reductions and data evaluations for was founded by the outstanding scientist Victor Ambartsum- CCD photometry in the globular cluster NGC 6864 ͑a tri- ian in 1946. First studies at BAO related with the instability modal HB Galactic Globular Cluster͒ acquired and initially phenomena taking place in the Universe, and this trend be- reduced by INI in Chile came the main characteristic of the science activity in Byura- G. Alcaino, F. Alvarado, with data obtained at VLT kan. Discovery of the stellar associations ͑1947͒, the hypoth- ͑FORS-1͒ ESO Paranal in a joint study with Gloria An- esis about activity of galactic nuclei ͑1958͒, the famous First dreuzzi, Vincenzo Testa, Gianni Marconi, and Roberto Buo- and Second Byurakan surveys ͑FBS, 1965-80, and SBS, nanno, analyzed the Galactic Globular Cluster NGC 6397, 1978-91͒, the discovery and study of many QSOs and Sey- covering a relatively wide area spanning radial distances fert galaxies, the discovery of some 1000 flare stars, dozens from the cluster center 1ЈϽrϽ9.8Ј, they present ͑V, V-I͒ of Supernovae, hundreds of Herbig-Haro objects and come- VLT-FORS1 observations of the Galactic Globular Cluster tary nebulae, works in the field of radiation transfer theory, NGC 6397. They derive accurate color-magnitude diagrams are the main scientific achievements of the Byurakan 2 ANNUAL REPORT ISAAC NEWTON INSTITUTE OF CHILE 3 astronomers. Markarian, Arakelian and Kazarian galaxies are 2.1 Main Scientific Results known to all astronomers working in the field of extragalac- Galactic Astronomy, Mauron, Azzopardi, Gigoyan, and tic astronomy. Among the most well-known astronomers Kendall ͑A&A 418, 77, 2004͒ have undertaken a new search who have worked at BAO are V.A. Ambartsumian, B.E. for cool N-type carbon ͑C͒ stars in the halo of our Galaxy Markarian, G.A. Gurzadian, M.A. Arakelian, L.V. Mirzoyan, based on the 2MASS survey. Candidates were first selected E.Ye. Khachikian, and E.S. Parsamian. V.A. Ambartsumian in the 2MASS Second Incremental Release database with has been the IAU President ͑1961-64͒, IAU Vice-President JHKs colors typical of red AGB C stars and Ks Ͻ 13, and ͑1948-55͒, twice the ICSU President ͑1968-72͒, he was the subsequently checked through medium resolution slit spec- President of the Armenian Academy of Sciences during troscopy. We discovered 27 new C stars plus one known 1947-1993 and the Director of BAO during 1946-1988. previously and two similar objects in the Fornax and Sculp- At present, BAO has some 70 researchers, including 9 tor dwarf galaxies. They determine and discuss the properties Doctors of Science and 38 Candidates of Science ͑Ph.D.͒. of the sample, including optical and near-infrared colors, ra- Many are members of IAU, EAS, EAAS ͑Euroasian Astron. dial velocities, as well as Ha emission and variability that are Soc.͒, and other international societies and organizations. frequent, all these characteristics being compatible with an Since the beginning of 2004, the Director is Haik Harutyu- AGB C-type classification. They adopt the view that all ob- nian. There are 3 scientific divisions and 12 research groups. jects are of AGB type, i.e. luminous and distant. Because the A number of associates teach at the Yerevan State University stream of Sagittarius dwarf galaxy is known to be the domi- ͑YSU͒, including 5 INI Armenian Branch members. nant source of luminous C stars in the halo, the authors chose The main fields of scientific activity at BAO are: to determine distances for the sample by scaling them on the • Search and multiwavelength studies of AGN and star- 26 known AGB C stars of the Sgr galaxy itself, which are burst galaxies, found to be, in the Ks-band, 0.5 mag less luminous than the • Infrared and radio galaxies, average LMC C stars for a given J-Ks color. The obtained distances of the halo stars range from 8 to 80 kpc from the • Young stellar objects and their environments, Sun. The examination of position and radial velocities shows • Physics of nebulae, that about half belong to the Sgr stream. The authors suggest • Variable stars, that numerous AGB C stars remain to be discovered in the • Clusters of galaxies, halo. Long term Ks-band monitoring would be of great value • Observational cosmology, to ascertain distance estimates through the period-luminosity • Theory of compact cosmic objects, relation, because a large fraction of their sample is probably made of Mira variables. The work is based on observations • Radiative transfer theory, made at the European Southern Observatory ͑ESO͒, Chile • Solar activity. and at the Haute Provence Observatory ͑OHP, France͒, to- The traditional methods for investigations are surveys, gether with data from the 2MASS project. spectroscopic, photometric and polarimetric observations, Movsessian, Magakian, Boulesteix, and Amram ͑A&A statistics, and direct and inverse theoretical problems. The 413, 203, 2004͒ have studied various manifestations of the Byurakan astronomers collaborate with scientists from outflow connected to the cometary nebula GM 3-12 ͑RNO France, Germany, Italy, UK, Spain, Russia, USA, Mexico, 124͒. The results of imaging and scanning Fabry-Perot inter- Japan, China, India, Chile, and other countries. The funding ferometry of GM 3-12 and Herbig-Haro object HH 376A are of science in Armenia is at very low level; however, the presented. The nebula is cone-shaped with the star IRAS Byurakan astronomers work actively due to the international 20359ϩ6745 at the apex, showing straight walls and two collaboration and grants, and valuable contribution in sci- probable helical arms. HH 376A is the bow shock structure ence. The main scientific instruments at BAO are the 2.6m in the collimated high velocity flow, directed by the axis of telescope and the 1m Schmidt telescope. BAO has a large the cone nebula, with shock velocity about 70-80 km s-1. archive of photographic plates, which are being digitized at The spatial and kinematical separation between bow shock present. The First Byurakan Survey ͑FBS͒ plates have been and Mach disk in HH 376A was not detected, which makes already digitized, and the Digitized First Byurakan Survey this object similar to HH 111. The Ha profiles in the vicinity ͑DFBS͒ database has been created. It is a unique low- of the source are double peaked. The high velocity compo- dispersion spectroscopic database covering 17,000 sq. deg. at nent can be attributed to the collimated flow. The work is high galactic latitudes and containing some 20,000,000 based on the observations collected with the Byurakan 2.6 m objects. telescope. Other astronomical centers in Armenia are the Yerevan Mickaelian ͑A&A, 2004, in press͒ has fulfilled a work on State University ͑YSU͒, Department of Astrophysics ͑sur- DSS1/DSS2 astrometry of 1101 FBS blue stellar objects. To veys, extragalactic astronomy͒, Departments of Theoretical establish the accuracy of the DSS1 and DSS2 ͑blue and red͒, and General Physics ͑physics of the neutron stars, theoretical measurements have been made for 153 AGN for which ab- astrophysics, galactic dynamics͒; the Yerevan Physics Insti- solute VLBI coordinates had been published. The rms errors tute ͑YerPhI͒, Departments of Theoretical Physics ͑cosmol- are: 0.45 arcsec for DSS1, 0.33 arcsec for DSS2 red, and ogy͒, and Cosmic Rays Department; and the Garni Space 0.59 arcsec for DSS2 blue in each coordinate, the corre- Astronomy Institute, with a few astronomers or physicists sponding total positional errors being 0.64 arcsec, 0.46 arc- working on astrophysical problems. sec, and 0.83 arcsec, respectively. The highest accuracy 4 ANNUAL REPORT

͑0.42 arcsec͒ is obtained by weighted averaging of the DSS1 hand they find that, at a flux limit of 0.02 count/s and at this and DSS2 red positions. It is shown that by using all three magnitude, only 40 Kandalyan ͑AJ, 2004, submitted͒ has DSS images accidental errors can be significantly reduced. made VLA observations of the OH megamaser galaxies at The comparison of DSS2 and DSS1 images made it possible 1.49 GHz and studied their radio properties. to reveal positional differences and proper motions for 78 Petrosian, Navasardyan, Cappellaro, McLean, Allen, Pa- objects ͑for 62 of these for the first time͒, including new nagia, Leitherer, MacKenty, and Turatto ͑AJ, 2004, submit- high-probability candidate white dwarfs, to find objects ted͒ have studied the Supernovae progenitors and their host showing strong variability, i.e. high-probability candidate galaxies. In another paper, Mannucci, Della Valle, Panagia, cataclysmic variables, and objects with slight extension in Cappellaro, Cresci, Petrosian, and Turatto ͑A&A, 2004, sub- their DSS2 images, candidate low-redshift QSOs and other mitted͒ have studied the supernova rate per unit mass of the AGN. host galaxies. Extragalactic Astronomy, Cannon, Skillman, Kunth, Lei- Theoretical Astrophysics, Nikoghossian ͑A&A 422, 1059, therer, Mas-Hesse, Ostlin, and Petrosian ͑ApJ 608, 768, 2004͒ has studied the radiative transfer in one-dimensional 2004͒ have studied the extended tidal structure in two Lya- inhomogeneous atmospheres. He uses Ambartsumian’s emitting starburst galaxies: Tol 1924-416 and IRAS 08339 method of addition of layers to show that various problems, ϩ6517. They present new Very Large Array ͑VLA͒ including the standard ones, of radiation transfer in a plane- C-configuration H I imaging of these galaxies. The effective parallel inhomogeneous atmosphere may be reduced to the resolution probes neutral gas structures larger than 4.7 kpc in solution of the Cauchy problems for linear differential equa- Tol 1924-416 and larger than 8.1 kpc in IRAS 08339ϩ6517. tions. This allows avoiding the known difficulties arising in Both systems are revealed to be tidally interacting: Tol 1924- solving the boundary-value problems to which the classical 416 with ESO 338-IG04B ͑6.6 arcmin ϭ 72 kpc minimum approach leads. For the purpose of exposition, the work deals separation͒, and IRAS 08339ϩ6517 with 2MASX with the simplest one-dimensional problem of multiple scat- J08380769ϩ6508579 ͑2.4 arcmin ϭ 56 kpc minimum sepa- tering for an atmosphere of finite optical thickness. The idea ration͒. The H I emission is extended in these systems, with of the approach is that the author starts with determining the tidal tails and debris between the target galaxies and their reflection and transmission coefficients of an atmosphere by companions. Since Lya emission has been detected from solving the initial-value problem for a set of linear differen- both of these primary systems, these observations suggest tial equations of the first order. After that the internal radia- that the geometry of the interstellar medium is one of the tion field is found immediately without solving any new factors affecting the escape fraction of Lya emission from equation. The approach is applied to several classical prob- starburst environments. Furthermore, these observations ar- lems of astrophysical interest. In particular, Nikoghossian gue for the importance of interactions in triggering massive evaluates the mean number of scatterings undergone by dif- star formation events. ferent types of photons. The transfer of radiation in an atmo- Veron-Cetty, Balayan, Mickaelian, Mujica, Chavushyan, sphere with arbitrarily distributed internal sources is consid- Hakopian, Engels, Veron, Zickgraf, Voges and Xu ͑A&A ered. Analytical solutions for these problems are obtained. 414, 487, 2004͒ have undertaken a project on optical identi- Simple recursion formulas are derived to find the radiation fication of ROSAT Faint Source Catalog ͑FSC͒ sources intensity emitted by a multicomponent atmosphere. The aimed at construction of a complete X-ray selected bright problem of multiple scattering of radiation with partial redis- AGN sample and discovery and study of new bright Seyfert tribution over frequencies is discussed to demonstrate the galaxies. The authors have cross-correlated the ROSAT-FSC generalization of the approach to the matrix case. The results of numerical calculations are given. catalog with the USNO-A2.0 catalog limited to objects brighter than Oϭ16.5 and then with the Minnesota Auto- mated Plate Scanner ͑MAPS͒ catalog. Each of the 3212 co- 2.2 Current Projects incidences was classified using the slitless Hamburg spectra. 493 objects were found to be extended and 2719 star-like. At present, the INI Armenian Branch members carry out Using both the extended objects and the galaxies known 14 large international projects with participation of scientists from published catalogs the authors built up a sample of 185 from the USA, France, Germany, Italy, UK, Spain, Japan, galaxies with O͑APS͒Ͻ 17.0 mag, which are high- China, Mexico, Russia, and Jordan. A few other astronomers probability counterparts of RASS-FSC X-ray sources. 130 from the Byurakan Observatory are involved as well. In frame of these projects, mutual visits of scientists have been galaxies have a redshift from the literature and for another 34 fulfilled and observations with the Byurakan 2.6m, Russian new spectra have been obtained with the Byurakan 2.6m and Special Astrophysical Observatory 6m, Observatoire de Guillermo Haro Observatory 2m ͑Mexico͒ telescopes. The Haute-Provence 1.93m telescopes, and the Hubble Space fraction of Seyfert galaxies in this sample is 20 correspond- Telescope ͑HST͒ have been carried out. Observations with ing sample of 144 high-probability counterparts among the the Space InfraRed Telescope Facility ͑SIRTF͒ are planned. star-like sources, the authors searched for very blue objects These projects are: in an MAPS-based color-magnitude diagram. Forty-one were already known AGN and for another 91 objects they ob- • Investigation of star formation regions in Our Galaxy tained new spectra, yielding 42 new AGN, increasing their ͑T. Magakian, T. Movsessian & E. Nikogossian, with number in the sample to 83. This confirms that surveys of the Armagh Observatory ͑UK͒ and MPIA, Heidelberg bright QSOs are still significantly incomplete. On the other ͑Germany͒ teams͒. ISAAC NEWTON INSTITUTE OF CHILE 5

• Jets and Outflows from Young Stellar Objects ͑T. Ma- 2.5 Organizational Affairs gakian & T. Movsessian, with Observatoire de Marseille ͑France͒ and Special Astrophysical Observa- H. Harutyunian and A. Mickaelian are the Co-Presidents tory ͑Russia͒ teams͒. of the Armenian Astronomical Society ͑ArAS͒. T. Magakian ͑ • Survey for Halpha emission line stars in dark clouds T. is the ArAS Vice-President and the Editor of the ArAS Elec- Magakian, T. Movsessian & E. Nikogossian, with tronic Newsletter, and E. Nikogossian, the Secretary of Kokugakuin University ͑Japan͒ team͒. ArAS. A. Gyulbudaghian, H. Harutyunian, T. Magakian, N. • Search and study of high galactic latitude carbon stars Melikian, T. Movsessian, A. Nikoghossian, and E. Nikogos- ͑K. Gigoyan, with Observatoire de Marseille and Mont- sian are members of the Scientific Council of BAO. A. Mic- pellier University ͑France͒ teams͒. kaelian is a member of the Executive Committee of the • Study of late-type variables ͑N. Melikian & A. Karape- Euro-Asian Astronomical Society ͑EAAS͒ and T. Magakian tian, with the University of Santiago de Compostela is a member of the EAAS Scientific-Technical Committee. ͑Spain͒ team͒. T. Movsessian is the Head of the Byurakan 2.6m telescope • Radiative transfer and Solar activity ͑A. Nikoghossian, Laboratory, and S. Balayan and K. Gigoyan are its respon- with IAP and Paris-Meudon ͑France͒ teams͒. sible observers. H. Harutyunian, T. Magakian, A. Mickae- • Study of Supernovae in nearby galaxies ͑A. Petrosian & lian, T. Movsessian, and E. Nikogossian have organized the H. Navasardyan, with the Padova University ͑Italy͒ ArAS III Annual Meeting in Byurakan. team͒. The INI Armenian Branch staff members have published • Study of Markarian and SBS galaxies ͑A. Petrosian, in 2004 5 papers in ApJ, AJ and A&A, 1 is in press, and 3 with the STScI ͑USA͒ team͒. more have been submitted. Some other papers are expected • Study of Starburst galaxies with HST ͑A. Petrosian, to be published/accepted/submitted till the end of the year. with the IAP ͑France͒ and STScI ͑USA͒ teams͒. 20 other papers have been published by the Armenian branch staff members in other journals ͑14 of them in Astrophysics͒, • Study of ROSAT AGN ͑A. Mickaelian, S. Balayan & S. Hakopian, with Hamburg and MPE, Garching ͑Ger- and in proceedings of conferences. many͒, Observatoire de Haute-Provence ͑France͒, INAOE ͑Mexico͒ and Beijing Observatory ͑China͒ teams͒. 3. THE INI BULGARIAN BRANCH • Spectroscopic study of bright QSOs and Seyferts ͑A. Mickaelian, with Observatoire de Haute-Provence The Isaac Newton Institute of Chile established its Bul- ͑France͒ team͒. garian Branch in July 2000. The formal Agreement was signed with Prof. Georgi Ivanov, head of the Department of • The Second Byurakan Survey ͑SBS͒͑L. Erastova, with UNAM and INAOE ͑Mexico͒ teams͒. Astronomy and the University Astronomical Observatory at the St. Kliment Okhridski University of Sofia. The staff of • Radio and IR studies of Markarian and megamaser gal- the Isaac Newton Institute in Bulgaria includes representa- axies ͑R. Kandalyan, with Al-Bayt University ͑Jordan͒ team͒. tives of all astronomical institutions in Bulgaria. These insti- tutions are: the Department of Astronomy at the St. Kliment • Digitization of the First Byurakan Survey ͑A. Mickae- Okhridski University of Sofia, the Institute of Astronomy lian, L. Erastova, S. Balayan & K. Gigoyan, with Universita di Roma La Sapienza ͑Italy͒ and Cornell and National Astronomical Observatory at the Bulgarian University ͑USA͒ teams͒. Academy of Sciences, and the Department of Physics, St. Konstantin Preslavski University of Shumen. The staff of the Bulgarian Branch of Isaac Newton Insti- 2.3 Participation in International Meetings tute consists of: Aleksander Antov, Ina Barzova, Jordanka The Armenian Astronomical Society ͑ArAS͒ III Annual Borissova, Peter Duchlev, Tsvetan Georgiev, Valeri Golev, Meeting was organized on August 30-31, 2004 in Byurakan; Ilian Iliev, Ljubomir Iliev, Georgi Ivanov, Dimitar Kolev, all the Organizing Committee consisted of INI Armenian Renada Konstantinova-Antova, Radostin Kurtev, Diana Branch members. Most of the members of the INI Armenian Kjurkchieva, Dragomir Marchev, Haralambi Markov, Nevi- Branch participated in the Meeting; K. Gigoyan, A. Gyul- ana Markova, Bojko Mihov, Petko Nedjalkov, Georgi budaghian, H. Harutyunian, R. Kandalyan, T. Magakian, A. Petrov, Tatiana Russeva, Liuba Slavecheva, Ivanka Stateva, Mickaelian, T. Movsessian and E. Nikogossian presented, Nikolai Tomov, Mima Tomova, Todor Veltchev, and Ivanka invited and contributed talks. A. Mickaelian has also partici- Yankulova. The Resident Director of the INI Branch in Bul- pated in the Joint European and National Astronomy Meet- garia is Valeri Golev, the head of Department of Astronomy ing ͑JENAM-2004͒ in September 2004 in Granada, Spain: since October 2003. Minisymposia No. 2 ͑a poster͒ and No. 5 ͑contributed talk͒. Founded in 1894, the Astronomical Observatory and De- partment of Astronomy of St. Kliment Okhridski Sofia Uni- 2.4 Ph.D. Theses versity is the oldest astronomical institution in Bulgaria which is the only one responsible for the university educa- In September 2004, S. Balayan defended his Ph. D. thesis tion at all three levels ͑bachelours, masters and doctors͒ in on Study of the blue stars of the Second Byurakan Survey. the field of astronomy and astrophysics in Bulgaria. Having a A. Karapetian, and H. Navasardyan are currently working on staff of 10 employers, the scientific activities of the Depart- their Ph.D. theses. ment cover the fields of stellar content of Local Group gal- 6 ANNUAL REPORT axies, OB associations, WR stars, AGNs, stellar pulsations other investigations, they conclude that their approximate ap- and variable stars. proach is actually able to provide consistent results. Addi- The Institute of Astronomy together with its National As- tionally, they studied the consequences of ‘‘fine tuning’’ tronomical Observatory at Rozhen, Rodopa Mountain, is the some of the direct and indirect parameters entering the WLR, biggest astronomical institution in Bulgaria. The staff of In- especially by accounting for different possible values of stel- stitute consists of about 70 employers both in Sofia and the lar reddening and distances. Combining their data set with Observatory. The Rozhen Observatory is the only major ob- the corresponding data provided by Herrero et al. ͑2002͒ and servatory in Bulgaria with its 2m Ritchey-Chretien-coude re- Repolust et al. they finally study the WLR for the largest flector and three smaller telescopes ͑60cm Cassegrain, 50/70 sample of Galactic O-type stars gathered so far, including an Schmidt camera, and a solar instrument͒. For more than 30 elaborate error treatment. The established disagreement be- years, the Rozhen Observatory was the biggest in South-East tween the theoretical predictions and the ‘‘observed’’ WLRs Europe yielding precedence to the 2.3m telescope of the being a function of luminosity class is suggested to be a Greeck National Observatory since fall of 2003. The main result of wind clumping. Different strategies to check this activities of the staff of the Institute of Astronomy are: to hypothesis are discussed, particularly by comparing the H␣ carry out fundamental research programs in a broad range of mass-loss rates with the ones derived from radio observa- fields in astronomy and astrophysics, and to maintain and tions ͑2004, A&A, 413, 693͒. secure the observational programs at Rozhen Observatory. Kurtev, R., Georgiev, L. et al. present a catalog of OB The Institute of Astronomy of the Bulgarian Academy of associations in IC 1613. Using an automatic and objective Sciences was established in 1954. Its staff also maintain a method 60 objects were found. The size distribution reveals smaller observatory around the town of Belogradchik in the a significant peak at about 60 parsecs if a distance modulus Northwest part of the country where two small telescopes of 24.27 mag is assumed. Spatial distributions of the detected operate. associations and H II regions are strongly correlated ͑2004, The St. Konstantin Preslavski University of Shumen was A&A, 413, 889͒. established 40 years ago as a regional university for North- Tomov, N., Zamanov, R. et al. analyze H␣ observations east part of Bulgaria. Some essential astronomical courses of the recurrent nova T CrB obtained during the last decade. are offered there by the Department of Physics where two For the first time the H␣ emission profile is analyzed after astronomers are employed as staff members. subtraction of the red giant contribution. Based on their new So far six papers are published in 2004 by the staff of the radial velocity measurements of the H␣ emission line they Bulgarian Branch of the Isaac Newton Institute of Chile. estimate the component masses of T CrB. It is found that the During the year the staff members of the Bulgarian Branch hot component is most likely a massive white dwarf. They are actively working in different fields of astrophysics. The estimate the inclination and the component masses to be Ӎ o” Ӎ Ϯ Ӎ Ϯ scientific highlights of the most significant papers can be i 67 , M WD 1.37 0.13 M ᭪ and M RG 1.12 0.23 M ᭪ , summarized in two broad main fields: respectively. The radial velocity of the central dip in the H␣ Ivanov et al. discovered new Milky Way star clusters can- profile changes nearly in phase with that of the red giant’s didates using the 2MASS Point Source Catalog. In a second absorption lines. This suggests that the dip is most likely paper of this series ͑Borissova et al., A&A accepted, 2003͒ produced by absorption in the giant’s wind. Their observa- the physical properties of the 2MASS new obscured Milky tions cover an interval when the H␣ and the U-band flux vary Way stellar cluster CC 01 were discussed. A catalog of OB by a factor of ϳ6, while the variability in B and V is much associations in the faint irregular Local Group galaxy NGC smaller. Based on their observations, and archival ultraviolet 1613 was presented by Borissova et al. ͑A&A accepted, and optical data they show that the optical, ultraviolet and 2003͒. The purpose of the paper, the fourth of IC 16131 H␣ fluxes strongly correlate. They argue that the presence of series of the authors, is to outline new boundaries of the an accretion disc can account for most of the observed prop- associations in this galaxy. erties of T CrB ͑2004, A&A, 415, 609͒. Markova N., Markov H., et al. study mass-loss and wind Kjurkchieva, D., Marchev, D. et al. present high- momentum rates of 29 Galactic O-type stars with luminosity resolution spectroscopic observations around the H␣ line and classes I, III and V by means of a pure H␣ profile analysis BVRI photometry of the eclipsing short-period RS CVn star and investigate to what extent the results compare to those WY Cnc. The solutions of their radial velocity curves and originating from a state-of-the-art, complete spectral analy- light curves yielded the following values for masses and radii ϭ ϭ ϭ sis. Their investigation relies on the approximate method de- of the components: M 1 0.84 M ᭪ , M 2 0.46 M ᭪,R1 1.06 veloped by Puls et al. ͑1996͒ which they have modified to R᭪,R2ϭ 0.65 R᭪. The measured rotational broadenings of account for the effects of line-blanketing. Effective tempera- the spectral lines correspond to equatorial velocities V1ϭ78 tures and gravities needed to obtain quantitative results from kmsϪ1 and V2ϭ49 kmsϪ1. The distortions of their multi- such a simplified approach have been derived by means of color light curve of WY Cnc were reproduced by two cool calibrations based on most recent spectroscopic NLTE analy- spots on the primary star. An increase of the out-of-eclipse ses and models of Galactic stars by Repolust et al. ͑2003͒ brightness by 0.1 mag in February 2001 was detected. Their and Martins et al. ͑2002͒. Comparing ͑i͒ the derived wind- spectra show H␣ line in emission from the secondary star. densities to those determined by Repolust et al. for 11 stars The chromospheric activity appeared also in the observed in common and ͑ii͒ the Wind-momentum Luminosity Rela- emission cores of the CaII H and K lines as well as the CaI tionship ͑WLR͒ for their sample stars to those derived by 6494 line ͑2004, A&A, 415, 231͒. ISAAC NEWTON INSTITUTE OF CHILE 7

Georgiev, T. B. et al. present BVR CCD photometry combining active scientific research with teaching for stu- down to limiting magnitude Bϭ23.5 mag for 232 starlike dents and tutorials in astrophysics. Many astrophysicists of objects and 11 diffuse objects in a 5Ј.4 ϫ 5Ј.4 field of Ho FSU were trained at the Crimean Observatory. Now the IX. The galaxy is a gas-rich irregular dwarf galaxy possibly Crimean Astrophysical Observatory ͑CrAO͒ remains one of very close to M 81, which makes it especially interesting in the largest scientific centers in the Ukraine and the FSU. the context of the evolution of satellite galaxies and the ac- CrAO possesses modern equipment for astrophysical ob- cretion of dwarf galaxies. Investigations of Ho IX were ham- servations over a wide spectral range from gamma-rays to pered by relatively large contradictions in the magnitude meter radio waves of stars and galaxies as well as the Sun scale between earlier studies. With their new photometry and solar system. The main part of the observatory is located they resolved these discrepancies. The color magnitude dia- at Nauchny, at an altitude of 600 meters. The instruments in ͑ ͒ gram CMD of HoIX is fairly typical of a star-forming use are: the 2.6-m Shajn telescope, two 1.25-m telescopes, dwarf irregular, consistent with earlier results. Distance esti- the 1.0-m Solar Tower telescope as well as a few other in- mates from their new CMD are consistent with Ho IX being struments. There are 350 employees including about 100 sci- very close to M 81 and therefore being a definite member of entists. the M 81 group, apparently in very close physical proximity The members of the Crimean Branch are actively working ͑ ͒ to M 81 2004, A&A, 423, 87 . in different fields of astrophysics. Due to scientific interests, Veltchev, T. and Nedialkov, P. et al. derive an average they entered on the 8 scientific projects: initial mass function ͑IMF͒ for 50 OB associations in the South-Western part of Andromeda galaxy, combining ultra- • ‘‘Compact binaries: Cataclismic variables, black violet photometry of Hill et al. ͑1995͒ and two datasets HST holes, symbiotic stars.’’ Investigators: Elena Pavlenko, photometry with JHKs photometry from the 2MASS ϩ I Elena Dmitrienko, Anatoly Tarasov, Oksana Antoniuk, band photometry from Magnier et al. ͑1992͒. The mean ex- Petr Petrov, and Natalya Bondar. The aim of this tinctions within the associations were estimated in two inde- project is to investigate the behavior of binaries in order pendent ways and the stellar masses were determined by use to study pecularities of their evolution. Active in pho- of probabilistic techniques. The derived slope of the IMF tometric, polarimetric and spectroscopic observations ⌫ϭ-1.59 Ϯ 0.09 is close to the universal Salpeter’s law and using the 2.6-m telescope equipped with a CCD Camera to recent estimates for massive stars’ IMF in the Galaxy and and a 1.25-m telescope equipped with a 5-channel, UB- in the Magellanic Clouds ͑2004, A&A, 426, 495͒. VRI photometer-polarimeter as well as a few other small telescopes. • ‘‘Surface anomalies of the chemically peculiar 4. THE INI CRIMEAN BRANCH stars.’’ Investigators: Victor Malanushenko, Igor Sa- The Isaac Newton Institute opened a Branch in Crimea, in vanov, Marina Mitskevitch, and Nina Polosukhina. The September 1997. The formal Agreement was signed by aim of the project is to broaden the knowledge of the Gonzalo Alcaino in Nauchny with Prof. Nikolay Steshenko, pecularities of the atmospheres of the chemically pecu- Director of the Observatory. Thereafter, the agreement, be- liar stars of the upper main sequence, using the coude tween the Crimean Astrophysical Observatory of Ukraine spectrograph of the 2.6-m telescope. and the Isaac Newton Institute of Santiago, Chile, was en- • ‘‘Continuum and emission lines variability in active dorsed in an official document signed in Kiev by the Minis- galactic nuclei.’’ Investigators: Vladimir Pronik, try of Sciences and Technology of Ukraine, represented by Sergey Sergeev, Elena Sergeeva, Yuri Golubinskiy, and the Vice-Minister, Y. Dotsenko. Alina Streblyanskaya. The objective of this project is to The current staff of the Isaac Newton Institute in Crimea investigate in detail the variability of emission lines in are: Ilya Alekseev, Oksana Antoniuk, Valery Bochkov, Var- the spectra of active galactic nuclei. The observations vara Butkovskaya, Natalya Bondar, Yuri Golubinskiy, Elena are performed on the 2.6-m telescope with a CCD de- Dmitrienko, Valentina Doroshenko, Vasily Haneychuk, Ly- tector. udmila Karachkina, Olesya Kozlova, Valery Kotov, Victor • ‘‘Variability of active galactic nuclei in optical and Malanushenko, Nelly Merkulova, Lubov Metik, Marina infrared continuum.’’ Investigators: Iraida Pronik, Mitskevich, Elena Pavlenko, Petr Petrov, Sergei Plachinda, Nelly Merkulova, Lubov Metik, and Valentina Dorosh- Nina Polosukhina, Natalia Primak, Valentina Prokof’eva- enko. The objective of the project is the detailed inves- tigation of the continuum variability of active galactic Mikhailovskaja, Iraida Pronik, Vladimir Pronik, Igor Sa- nucei in time scales of hours, days, months, and years vanov, Sergey Sergeev, Elena Sergeeva, Nikolai Sha- using tight series of the observations which have been khovskoy, Alina Streblyanskaya, Anatoly Tarasov, Taisiya carried out at the Crimean Observatory since 1989 us- Tarasova, Teodor Tsap, Yuri Tsap, Yuri Yefimov, and Fedor ing the 1.25-m telescope equipped with the UBVRI Velichko. The Resident Director of the INI Branch is Nelly double- image chopping photometer-polarimeter. Merkulova. • ‘‘Study of selected blazars structure from photom- The Crimean Observatory was the first major observatory etry and polarimetry.’’ Investigators: Yuri Yefimov, ͑ ͒ of the former Soviet Union FSU to enter the age of astro- Nikolai Shakhovskoy, and Natalia Primak. The main physics. The beauty of the observatory site, the telescopes purpose of the project is to study the structure of some and the instruments together with a rich history and the cur- bright blazars using prolonged ͑several years͒ simulta- rent scientific activity of the astronomers make the Observa- neous photometric and polarimetric observations in op- tory a quite attractive place. For many years it was unique in tical regions from ultraviolet to near infrared. The ob- 8 ANNUAL REPORT

servations are carried out with the 1.25-m telescope bursts that occurred in January-March 2002. The polarization equipped with UBVRI double-image chopping photo- of the object is mainly due to interstellar polarization ͑P polarimeter. ϭ2.48%͒. Intrinsic polarization up to about 0.7% at 5000 A • ‘‘Seismology of the Sun and stars.’’ Investigators: is present during the second maximum of the object ͑Febru- Valery Kotov, Teodor Tsap, and Vasily Haneychuk. ary 2002͒. This intrinsic component increases toward shorter The aim of this project is to improve our knowledge wavelengths but the limited spectral coverage ͑5000-7500 A͒ about the Solar interior, rotation, magnetic activity and does not allow conclusive inferences about its origin. A cycle using the observations of the global Solar oscilla- strong depolarization across the H␣ profile is observed. The tions and mean magnetic field of the Sun obtained with interstellar polarization gives a lower limit to the reddening the Solar Tower telescope. of E͑B-V͒Ͼ0.28, with E͑B-V͒ϳ0.5 being the most probable ‘‘Solar and stellar activity.’’ • Investigators: Sergei value. A normal ratio of total to selective absorption ͑Rv Plachinda, Taisiya Tarasova, Ilya Alekseev, Olesya Ko- ϭ3.22Ϯ0.17͒ was derived from the wavelength of maximum zlova, Yury Tsap, and Varvara Butkovskaya. The aim ͑ ͒ of the project is to study magnetohydrodinamical pro- interstellar polarization. This suggests a low if any contri- cesses and magnetic activity on the Sun and on the bution by circumstellar material with a peculiar dust to gas main- and pre-main sequence cool and red stars. Inves- ratio. A polarimetric map of a portion of the light echo tigations are based on the theoretical researches, nu- shows a complex polarization distribution reaching Pmax merical simulations, direct measurements of stellar ϭ45%. Paper is based on observations collected at Padua magnetic fields, photometric and spectrophotometric Astronomical Observatory at Asiago and Crimean Astro- observations, obtained with the use of the 2.6-m Shajn physical Observatory. telescope equipped with Stokesmeter, and 1.25-m tele- A.E. Tarasov participated in a cooperative spectroscopic scope equipped with a 5-channel, UBVRI photometer- observations of the Herbig Be star HD 200775 ͑Pogodin polarimeter. et al. 2004͒. High-resolution spectroscopy of this star was • ‘‘Physical researches of Solar system small bodies.’’ obtained within a framework of an observing programme in Investigators: Valentina Prokof’eva-Mikhailovskaja, 2000-2002. A new high-activity phase of the object’sH␣ line Lyudmila Karachkina, Valery Bochkov, and Fedor occurred in the middle of 2001 in full agreement with a Velichko. The aim of this project is to broaden the 3.68-year periodicity predicted earlier. A complicated picture knowledge on structures and surface characteristics of asteroids belonged to different spectral types and differ- of the H␣ line profile variability near the activity maximum ent asteroid’s families. The 0.5 meter meniscus tele- phase turned out to be very similar to that observed during scope coupled with the high sensitive digital television the previous one in 1997. Variations of the radial velocity system is used for photometric and spectrophotometric with the activity phase are detected in the HeI, SiII, and SII observations of asteroids. F.P. Velichko is working at photospheric lines. The observed phenomena are interpreted Research Institute of Astronomy, Kharkiv Karazin Na- in the framework of a model in which the star, together with tional University. He uses the 0.7 meter telescope and its gaseous envelope, is a component of an eccentric binary CCD detector for photometric observations of asteroids. system. A preliminary orbital solution is derived, and the I.Yu. Alekseev participated in a multiwavelength observ- system’s parameters are estimated from the radial velocity ing campaign conducted during 2000 March on the flare star curves of the H␣ emission line. It is found that the orbital AD Leo ͑Hawley et al. 2003͒. Simultaneous data were ob- eccentricity is about 0.3, the mean companion separation is tained from several ground- and space-based observatories, about 1000 solar radii, and the secondary companion is most including observations of eight sizable flares. The correlation likely to be a pre-main sequence object of about 3.5 solar of line and continuum emission in the optical and ultraviolet masses. The importance of coordinated spectroscopic and in- wavelength regimes, as well as the flare energy budget are terferometric observations at different phases of the object’s discussed in the paper. It was found that the emission prop- activity for further understanding the properties of the sys- erties are remarkably similar even for flares of very different tem is emphasized. evolutionary morphology. This suggests a common heating V.T. Doroshenko participated in a spectral monitoring mechanism and atmospheric structure that are independent of program for the Seyfert galaxy NGC 5548 which have been the detailed evolution of individual flares. The Neupert ef- carried out between 1996 and 2002 with the6mand1m fect, chromospheric line broadening, and velocity fields ob- telescopes of SAO ͑Russia͒ and with the 2.1 telescope of served in several transition region emission lines are also Guillermo Haro Observatory ͑GHO͒ at Cananea, Mexico discussed. The latter show significant downflows during and ͑Shapovalova, Doroshenko et al. 2004͒. High-quality spectra shortly after the flare impulsive phase. Observations obtained with S/NϾ50 in the continuum near H␣ and H-beta were are broadly consistent with the solar model of chromospheric obtained, covering the spectral range 4000-7500 A with a evaporation and condensation following impulsive heating ͑4.5 to 15͒A-resolution. It was found that both the flux in the by a flux of nonthermal electrons. These data place strong lines and in the continuum gradually decreased, reaching constraints on the next generation of radiative hydrodynamic minimum values during May-June 2002. In the minimum models of stellar flares. state, the wings of H␣ and H-beta became extremely weak, Yu.S. Efimov participated in polarimetric and spectro- corresponding to a Sy1.8 type, not to a Sy1, as observed polarimetric monitoring of V838 Monocerotis ͑Desidera previously when the nucleus was brighter. The line profiles et al. 2004͒. Observations were performed at the Asiago and were decomposed into variable and constant components. Crimean observatories during and after the multiple out- The variable broad component is well correlated with the ISAAC NEWTON INSTITUTE OF CHILE 9 continuum variation. It consists of a double peaked structure monitor several dozen objects as often as possible. The CCD with radial velocities Ϯ1000 km/s relative to the narrow camera AP7p was mounted in the prime focus of the tele- component. A constant component, whose presence is inde- scope. The camera has a set of B-V-R-R1-I filters, where the pendent of the continuum flux variations, shows only narrow filter designated as R1 represents closely Cousin’s filter I, emission lines. The mean, rms, and the averaged over years, while other filters represent closely standard Johnson’s fil- observed and difference line profiles of H-beta and H␣ reveal ters. As a rule, for each object not less than four images per the same double peaked stricture. The relative intensity of night in each filter have been acquired. The unbiased, dark- these peaks changes with time. During 1996, the red peak subtracted, and flat-fielded images were then measured. All was the brightest, while in 1998-2002, the blue peak became photometric measurements were obtained by the method of the brighter one. Their radial velocities vary in the ͑500- the aperture photometry. The light curves were nightly aver- 1200͒ km/s range. In 2000-2002 a distinct third component aged and analyzed. A cross-correlation analysis has been appeared in the red wing of H␣ and H-beta line profiles. The performed by using interpolation cross-correlation function radial velocity of this feature decreased between 2000 and ͑ICCF͒. A lag at CCF peak and CCF centroid has been com- 2002: from the observed profiles, from ϩ͑2500-2600͒ km/s puted. The computed lag ranges from tenths of a day to to ϩ2000 km/s and is clearly seen on the difference profiles. several days, and it is positive ͑by the mean V, R, I bands lag The fluxes of the various parts of the line profiles are very behind B͒ in most cases with except for few cases for filter well correlated with each other and also with the continuum V. In some cases the lag is greater than zero with more than flux. The blue and red parts of the line profiles at the same 3␴ confidence. The lag is systematically less for the filter V radial velocities vary in an almost identical manner. Shape than for the red filters and the lag determined from the CCF changes of the different parts of the broad line are not cor- ͑cross-correlation function͒ centroid is systematically greater related with continuum variations and, apparently, are not than the lag determined from the CCF peak. It is found that related to reverberation effects. Changes of the integral the lag scales with luminosity as Lb, where bϷ0.4Ϫ0.5. Balmer decrement are, on average, anticorrelated with the This lag is attributed to the light time travel effect, so it continuum flux variations. This is probably due to an in- reflects geometrical size of the region that emits optical con- creasing role of collisional excitation as the ionizing flux tinuum. A model in which optical emission is mainly re- decreases. The behavior of the Balmer decrement of the vari- processed emission that arise in a disk heated by point-like ous parts of the line profiles was different in 1996-2000 as X-ray source above this disk is considered. The modeled compared with the 2001 behavior. The results obtained favor spectrum is dropped down toward UV. Stronger UV fluxes the formation of the broad Balmer lines in a turbulent accre- can be provided by smaller distance and, of course, there tion disc with large and moving ‘‘optically thick’’ inhomo- must be a spectral component related to the heating disk by geneities, capable of reprocessing the central source accretion. In fact, the X-ray source can be extended spatially. continuum. In the last decade, it has been shown that satellites of Different spectral bands from X-ray to infrared in Active asteroids do exist. Observations and modelling of rotational Galactis Nuclei are often show correlated, although not iden- characteristics of binary systems are very important for the tical, variations in flux. It suggests that some fraction of the understanding of asteroid composition and collisional evolu- primary emission from one continuum band is reprocessed to tion. They allow a determination of the bulk density of these some other bands. Interband lags can identify a primary con- bodies—a parameter that is otherwise very difficult to obtain. tinuum band that provide the driving force and can point to Photometric observations can indicate binary asteroids when the size of the regions of the secondary ͑reprocessed͒ emis- they show two-period lightcurves. Usually the shorter peri- sion. The variability amplitude increases toward shorter ods are assotiated with the rotations of primary objects while wavelengths. The X-rays have largest amplitude and most the longer ones with the orbital rotations and/or rotations of rapid ͑in timescale of hours͒ variations, which could argue secondaries when they are synchronous. The asteroid 90 An- that the X-rays are the primary emission. The UV and optical tiope is a double asteroid with similar components of diam- fluxes usually show highly correlated variations. It is be- eter 85 km separated by 170 km. Antiope is a member of the lieved that the UV/optical emission is produced, at least in Themis family. CCD observations of this asteroid were car- part, by the optically thick blackbody component ͑accretion ried out at seven observatories ͑Borowiec, Kharkiv, Pic du disk͒, a signature of which is the so-called blue bump, the Midi, Chateau Renard, Les Engarouines, Ottmarsheim, and excess flux observed in spectra of AGNs. The X-rays can be Durtal͒ on 31 nights from December 2002 through April reprocessed into optical/UV photons by heating this compo- 2003. F.P. Velichko participated in these observations nent, but there might be inverse reprocessing of the ͑Michalowski, Bartczak et al. 2004͒. The results show two- optical/UV into X-rays in a hot media. There were several component lightcurves with each showing the same period of attempts in finding a connection between X-rays, UV, and 16.505Ϯ0.002 hours. The first component is associated with optical light curves. S. G. Sergeev, V.T. Doroshenko, Yu.V. the rotation of the two non-spherical bodies of the system; Golubinskiy, N.I. Merkulova, and E.A. Sergeeva ͑2004͒ de- the second one is due to eclipses/occultations in the binary termine interband lags between variations in B band and system. The lightcurves suggest that Antiope is an ‘‘almost variations in V, R, I bands for 14 active galactic nuclei. At synchronous system’’ with orbital period of 16.5051 the end of 2001 an intensive monitoring of active galaxies Ϯ0.0002 hours and a little shorter rotational one of 16.5047 have been started at the Crimean Astrophysical Observatory Ϯ0.0002 hours. Authors tried to predict the lightcurves for with the 70-cm telescope. The aim of the program is to the next two oppositions. According to their model, there 10 ANNUAL REPORT should be no mutual phenomena during the April 2004 op- • The spectrophotometric catalog contained the data on position. In July 2005, the occultations/eclipses should be the energy distribution in the spectra of thousands of clearly visible. If their model is correct, the shift of the rota- stars. tion maxima with respect to the occultation minimum should • The spectral Catalog of some dozens of Planetary be observed. The new lightcurves from these two apparitions Nebulae. are required to revise the model presented in the paper of the • The discovery of some peculiar objects representing the binary system of the asteroid 90 Antiope. transient stage between a star with extended atmosphere F.P. Velichko participated in photometric observations for and a planetary nebula. three main belt asteroids: 52 Europa ͑1995, 1997, 1999, • The multicolor photoelectric observations of more than 2000͒, 115 Thyra ͑1995, 1996, 1998, 2000͒, and 382 Dodona twenty irregular stars. ͑ ͒ 1996, 1998, 1999, 2001 . Observations have been carried • The estimation of the formation epoch of the galactic out at seven observatories. Using all available lightcurves, clusters the spin vectors, senses of rotation, and shape models of • The new method of structure dynamics based on the these three asteroids have been determined or refined corresponding generalization of the Infeld’s method in ͑Michalowski, Kwiatkowski et al. 2004͒. the common relativity. • Discovery of some moving features in spectra of some Seyfert galaxies. 5. THE INI KAZAKHSTAN BRANCH • The revealing of the altitude variations, dividing strato- The Isaac Newton Institute opened its Kazakhstan Branch sphere aerosolize into layers, based on monitoring of in April 2000. The formal Agreement has been signed with atmosphere. Prof. Anatoliy Kurchakov, Director of the Fessenkov Astro- • The large cycle of the searches on analysis of the zonal physical Institute of Kazakhstan. structure of Jupiter’s cloudy cover. The staff of the Isaac Newton Institute in Kazakhstan are: ͓ ͔ Gauhar Aimanova, Elena Baturina, Leonid Chechin, Edward The object K1-9 with strong NIi emission lines was Denissyuk, Sergey Efimov, Vladimir Kardopolov, Andrey included in the Perek and Kohoutek Catalog of Planetary Kharitonov, Ludmila Knyazeva, Ludmila Kondratyeva, Ana- Nebulae, but later it was considered to be an H Ii region. Our toliy Kurchakov, Tuken Omarov, Chingiz Omarov, Larisa results show that in addition to the low-excitation emissions ͓ ͔ Pavlova, Marina Rud, Lubov Shestakova, Vladimir Teresh- there are He Ii and O Iii emission lines in its spectrum, and chenko, Rashit Valiullin and Emmanuil Vilkoviskij. The the effective temperature of the central star is more than Resident Director of the INI Branch is Anatoliy Kurchakov. 54 000 K. Thus we conclude that K1-9 is indeed a planetary ͓ ͔ ͓ ͔ The beginning of the history of astronomy in Kazakhstan nebula. Distribution of O Iii and NIi emission lines re- was connected with such remarkable event as the solar flect a ring-like structure with a clear minimum in the centre eclipse that took place on 21 September, 1941. When the of the nebula. Hydrogen lines almost fail to show the central observations of the solar eclipse were completed, some as- gap. K1-9 has the backward proper motion with systemic ϭ tronomers from Moscow and Leningrad stayed in Alma-Ata velocity RV 60.2 km s-1. The central hydrogen compo- and organized The Institute of Astronomy and Physics. nent moves relative to the nebula with a pecular velocity of ͑ Then, in 1950, the Astrophysical Institute was distinguished about -50 km s-1, Kondratyeva, L. N. & Denissyuk, E. K. ͒ from as a self-maintained organization. A&A, 411, 477 . The actual staff of the Institute consists of 122 members, In 2004 the photometric and spectral observations of Her- 60 of them are scientific researches. The major activities are: big AEBE stars, which began in 2000, were went on by A. ͑ ͒ physics of nebulae and star-forming regions, dynamics of Kurchakov and F. Rspaev [email protected] . The gravity systems, absolute spectrophotometry of stars, study whole List of objects includes Herbig AEBE stars: MWC ␣ of active Galaxies, physics of the Moon and planets, Solar 314, MWC 340, V1685 Cyg, V594 Cas, AB Aur, LkH ␣ physics, the artificial Earth’s satellites. The Institute manages 215,HD 259431, OY Gem and TTau stars: LkH 330, RY the following two observatories: ͑1͒ The Observatory ͑Al- Tau, T Tau, GW Ori. Up to date processing of data for V 594 ␣ maty, Kamenskoe Plato͒ which possesses: a 70 cm telescope Cas is finished. During observations of V 594 Cas its H ͑ Cassegrain͒, equipped with spectrograph for faint emission profile changed once and again from P Cyg I to P Cyg III. Its objects, such as galaxies with active nuclei, planetary nebu- spectral parameters were also varied. The equivalent width ͑ ͒ m m lae, stars with emission spectra. a 60 cm telescope ͑Casseg- EW - within 55 - 95A, the V-brightness: 10 .5-10 .8, ͑ ͒ m m ͑ ͒ m m rain͒ of ‘‘Karl Zeiss’’ enterprise. It is used for the study of B-V :0 .58-0 .67, V-R :0 .68-0 .76. The clear cor- ͑ ͒ planets. ͑2͒ Assy- Turgen Observatory ͑Zailijskoe Ala-Tau, relation of EW value with V magnitude and B-V was re- Assy- Turgen plato͒ possesses: a 1-m telescope of ‘‘Karl vealed, i.e., EW decreases with decreasing of V value, but at ͑ ͒ Zeiss’’ enterprise, which is in use since 1981; This instru- the same time—with increasing of B-V ! Quite another pic- ment is equipped with electrophotometer for measurement of ture was observed during December, 2002- February, 2003. ␣ polarization of object’s radiation, and a spectrograph for a At that time H profile underwent the abrupt changes, down study of nebulae and stars. It has as well a 1.5m telescope. to the vanishing of absorption component, and equivalent The main scientific achievements can be summarized as: width fell up with decreasing of star’s brightness. During 2004 the spectral and photometric observations of • The atlases of nebulae, which became the world planetary nebulae and symbiotic stars were continued by L. standards. Kondratyeva. In particular, two objects were studied in de- ISAAC NEWTON INSTITUTE OF CHILE 11 tails: M1-77 and K4-46. The first one was included into one of the biggest and oldest cities in Russia, lying on the Catalog of planetary nebulae. But as it was shown by the river Volga, about 750 km east of Moscow. The staff mem- author, actually it is a symbiotic system. The second object is bers belong to both astronomical centers in Kazan and Ud- known to be a symbiotic star. Some spectral and physical murt State University ͑Izhevsk city͒. variations were revealed, when its modern spectrum was The staff of the Isaac Newton Institute in Kazan are: Al- compared with those, obtained earlier. maz Galeev, Askar Ibragimov, Ludmila Mashonkina, Vitalij Spectrophotometric observations of stars, which are Neustroev, Antonina Nefedjeva, Yuri Nefedjev, Naufal Riz- known to have planetary systems, were continued by V. vanov, Nail Sakhibullin, Ramil Shaimukhametov, Valery Tereshchenko. Suleimanov, Vladislav Shimansky and Nelli Shimanskaya. In 2004 the spectral study of some Seyfert nuclei were The Resident Director of the INI Branch is Valery carried out by E. Denissyuk and R. Valiullin. Comparing of Suleimanov. spectra, obtained with the same telescope and optical appa- The Astronomy Department of Kazan State University is ratus within large time interval ͑about 20-25 years͒, let to the oldest Astronomy Department in Russia. It was estab- find those AGN, which show noticeable variations. It is sup- lished in 1810. One of the first students of the Astronomy posed to study such perspective objects in details. Department was Nikolaj Lobachevsky. The staff of the De- The theoretical group ͑E. Vilkoviskiy, S. Efimov, E. Ba- partment includes two professors, eight associate professors, turina͒ continued theoretical investigations of active galactic five tutors and seven scientific researchers. The main fields nuclei ͑AGN͒ and creation of theoretical models of AGNs. of research are stellar atmospheres, chemical evolution of The methodological approach to the theory is based on the Galaxy, accretion disks, pre-cataclysmic and cataclysmic ‘‘Interacting Subsystems’’ approach worked out by E. Vilko- variable stars, CCD photometry of variable stars, gravita- viskij. According to this approach, AGNs consist of three tional lenses and X-ray sources, celestial mechanics, meteors main subsystems: central massive black hole ͑MBH͒, com- and geodesy. pact stellar cluster ͑CSC͒, and the gas subsystem ͑GS͒. The The Engelgardt Astronomical Observatory of Kazan State last, in its turn, consists of the accretion disk ͑AD͒, obscuring University is one of the best known astronomical observato- torus ͑OT͒, hot gas flowing from the surface of AD, and ries in Russia. It was opened in 1901 in 27 km west from small clouds of cold gas imbedded into the hot gas. One of Kazan. The current staff of the observatory consist of about the ‘‘hot problems’’ attracting the attention of investigators 10 scientists, including three professors. The research areas during the last decade is the nature of matter outflows from are astrometry, selenodesy, and meteor astronomy. AGNs. Creation of the general theory of matter outflows The Astronomy Department and Engelgardt Astronomical from AGN as well as detailed numerical models of the cor- Observatory have two mountain observational bases. 1. In responding absorption spectra in the UV and X-ray bands are 1975 the North-Caucasus Astronomical Station was built the main goals of the investigations of the group. The hot-gas near the 6-m telescope ͑BTA͒ of Special Astrophysical Ob- wind is supposed to fill the internal hole of the OT. The servatory of the Russian Academy of Science. The main tele- interaction of the wind with cold clouds at the internal sur- scope is a 40-cm Zeiss astrograph for observations of vari- face of the OT partly entrains these clouds into the wind. The able stars, asteroids and comets. A few new asteroids were large clouds fragment into the smaller one producing the discovered by using this astrograph. 2. In 1998, a new joint two-phase outflow along a conical surface. Thus AGNs with 1.5-m telescope of Kazan University, which is now named ͑ ͒ broad absorption lines the BAL-AGNs are included into RTT150 ͑Russian-Turkish Telescope͒, has been installed at the standard ‘‘geometrical unification scheme’’ as the objects the TUBITAK National Observatory ͑Turkey͒. This is a joint intermediate between AGN-1 and AGN-2. In the transition instrument of Kazan State University, Space Research Insti- layer, the two-phase gas dynamics demand consideration of tute ͑Russia͒ and TUBITAK ͑Turkey͒. The observatory is the drag forces between the cold clouds and the hot gas and located near of Antalya ͑Turkey͒ at the distance of about 50 the radiation pressure forces acting on the cold clouds. The km at the altitude of 2500 m above sea level. This telescope radiation transfer calculations take into consideration the is equiped by 2kx2k CCD cameras and will be equiped by two-phase ‘‘cloudy’’ structure of the moving cold gas. The spectrometers in a near future. A CCD photometry of a vari- second direction of the research of the group of Prof. Vilko- able stars, gravitational lenses and gamma-ray/X-ray sources viskij is the investigations of the structure of a compact stel- are carried out at present time. For example, one of the lar cluster in the AGN center, taking into account both inter- brightest optical afterglow gamma-ray burst in March 29, actions between stars and the interaction of the stars with an 2003, has been observed during few months. accretion disk. The researchers incorporated to the Kazan Branch are working in the following three fields of investigations: 6. THE INI KAZAN BRANCH • Abundances of chemical elements in stellar atmo- The Isaac Newton Institute opened its Kazan Branch in spheres: Researchers: Nail Sakhibullin, Ludmila Mas- March 2003. The formal agreement has been signed with honkina, Nelli Shimanskaya, Almaz Galeev and Prof. Nail Sakhibullin, Director of the Engelgardt Astro- Vladislav Shimansky. The aim of the project is the LTE nomical Observatory and Head of the Astronomy Depart- and non-LTE analysis of chemical composition of ment of Kazan State University in Russia. The Kazan State solar-like stars. The high dispersion spectral observa- University was established in 1804 and it is one of the oldest tions from western observatories, 6-m telescope SAO universities in Russia with high scientific potential. Kazan is ͑Russia͒ and 2-m telescope of the Ukrainian Terscol 12 ANNUAL REPORT

Station are used. These investigations give observa- grams is rather good provided the mean value of the mass- tional restrictions on the chemical evolution of the Gal- transfer rate ϽM˙ Ͼ ϳ 5ϫ1016 gsϪ1. Three spatially sepa- axy. rated sources of H␣ emission can be distinguished within • Accretion disks and related astrophysical objects: this approach. The structure of the tomogram depends on the Researchers: Valery Suleimanov, Askar Ibragimov, relative contributions of these sources to the H␣ emission Vladislav Shimansky, Nail Sakhibullin, Vitalij Neus- and is expected to vary from night to night ͑2004, A&A, troev. The aim of the project is investigations of differ- 421, 1131͒. ent type astrophysical objects with accretion disks, such as cataclysmic variables, supersoft X-ray sources, Ga- lactic black hole candidates and active galactic nuclei. 7. THE INI KIEV BRANCH The close binary systems without accretion disks but The Isaac Newton Institute opened its Kiev Branch in with strong irradiations of secondary star are also August 2000. The formal Agreement has been signed with investigated. These researchers give a best understand- Prof. Peter Berczik, Deputy Director, Main Astronomical ing of the physical processes in accretion disks and pa- Observatory in Kiev of the National Academy of Sciences of rameters of accretion disks and close binary systems. Ukraine. • Astrometry and selenodesy: Researchers: Naufal Riz- The staff of the Isaac Newton Institute in Kiev are: Peter vanov, Antonina Nefedjeva, Yuri Nefedjev and Ramil Berczik, Yurij Fedorov, Victor Khalack, Pavel Korsun, Yurij Shaimukhametov. The aim of this project is investiga- Kyzyrov, Pavel Malovichko, Sergey Nosov, Yakiv Pav- tion of different modern astrometric catalogs accuracy lenko, Boris Shakhov, Leonid Shulman and Boris Zhilyaev. and the border zone of the Moon. The Resident Director of the INI Branch is Boris Zhilyaev. Suleimanov, V. et al. present a detailed analysis of the The Main Astronomical Observatory ͑MAO͒ of the Na- lightcurve of CAL 87 that clearly has shown that the high tional Academy of Sciences of Ukraine came into being in optical luminosity comes from the accretion disc rim and can 1944. The Observatory is situated 12 km from the center of only be explained by a severe thickening of the disc rim near Kiev, in the Golosiiv forest. Since 1975 MAO is headed by the location where the accretion stream impinges. This area Ya.S. Yatskiv, Member of the NAS of Ukraine. The depart- is irradiated by the X-rays where it faces the white dwarf. ments of fundamental astrometry, photographic astrometry, Only if the reprocessing rate of X-rays to optical light is solar physics, and astrophysics were organized in 1958. At high, a luminosity as high as observed can be understood. present MAO includes the departments of astrometry, phys- But a recent detailed study of the soft X-ray radiation repro- ics of stars and galaxies, cosmic geodynamic, cosmic plasma cessing in supersoft X-ray sources has shown that the effi- physics, physics of bodies of the solar system, solar physics, ciency is not high enough. We here propose a solution for the department of experimental astrophysics and atmospheric this problem. As already discussed in the earlier lightcurve optics, astrospace information and computing center. The analysis the impact of the accretion stream at the outer disc Observatory offers postgraduate studentship and has a spe- rim produces a ‘‘spray,’’ consisting of a large number of cial academic council for conferring candidate’s and doctor’s individual gas blobs imbedded in a surrounding corona. For degrees in astronomy, astrophysics and engineering sciences. the high mass flow rate this constitutes an optically thick The Observatory Library contains some 66,000 printed vertically extended screen at the rim of the accretion disc. books and journals. MAO has a publishing department, ex- We analyse the optical properties of this irradiated spray and perimental designing subdivisions. etc. MAO publishes the find that the multiple scattering between these gas blobs journals Kinematics and Physics of Celestial Bodies and leads to an effective reprocessing of soft X-rays to optical Space Science and Technology and the Astronomical light as required by the observations ͑2003, A&A, 401, Calendar. 1009͒. In 1970-1991 the Astrophysical Observatory on Peak Ter- N.R. Ikhsanov, V.V. Neustroev, and N.G. Beskrovnaya, skol in the Northern Caucasus ͑altitude 3100 m, near moun- study the properties of the close binary AE Aqr, they indicate tain Elbrus͒ was constructed by MAO as its high-altitude that the mass transfer in this system operates via the Roche observation station. At present this observatory is a joint lobe overflow mechanism, but the material transferred from venture of the NAS of Ukraine and the Russian Academy of the normal companion is neither accreted onto the surface of Sciences. It forms part of the International Research Centre the white dwarf nor stored in a disk around its magneto- for Astronomy, Medicine and Ecology. This Centre is sphere. As previously shown, such a situation can be realized headed by Dr. V. Taradii. The equipment of the Terskol if the white dwarf operates as a propeller. At the same time, Station consists of the 2-meter Ritchey-Chretien telescope, the efficiency of the propeller action by the white dwarf is the Zeiss-600 telescope and two solar telescopes. Yu.I. Fe- insufficient to explain the rapid braking of the white dwarf, dorov, and B.A. Shakhov reported on a work the propagation which implies that the spin-down power is in excess of the of energetic charged particles in a magnetic field with a ho- bolometric luminosity of the system. To avoid this problem mogeneous regular component. On the basis of the Boltz- we have simulated the mass-transfer process in AE Aqr as- mann equation the analytical expressions for particle density suming that the observed braking of the white dwarf is gov- and anisotropy are derived under instantaneous isotropic in- erned by a pulsar-like spin-down mechanism. We show that jection of particles into the scattering medium. Starting from the expected H␣ Doppler tomogram in this case resembles the set of equations for spherical harmonics of the distribu- the tomogram observed from the system. We find that the tion function the new transport equation taking into account agreement between the simulated and the observed tomo- the second harmonic has been carried out. The solution of ISAAC NEWTON INSTITUTE OF CHILE 13 this transport equation is reached and comparison with ana- of the Institute is after P.K. Sternberg, Professor of Moscow lytical solutions of the kinetic equation is performed. The University and Director of its observatory, an expert in pho- telegraph equations for particle density and flux are derived tographic observations of the sky as well as in geodesy, and and their solutions are analyzed. The transport of energetic also an active participant of the 1917 revolutionary events in particles under multiple small angle scattering is considered. Russia. In 1931, three astronomical institutions of Moscow: V.R. Khalack et al. reconstruct the complex magnetic Research Institute for Astronomy and Geodesy, State Astro- field in the Ap star HD 187474 within the frame of the point physical Institute, and the University Observatory merged to field source model, where virtual magnetic charges are dis- form Sternberg Astronomical Institute. This research insti- tributed in the stellar body. The best-fit model describes suf- tute is the base for astronomical education in the Moscow ficiently well the observed nonsinusoidal variability of the University. Its fields of research cover practically all fields of mean magnetic field modulus and the sinusoidal behavior of modern astronomy and astrophysics. the mean longitudinal magnetic field with the phase of stellar The staff of the Isaac Newton Institute Moscow Branch rotation. The best fit provides discrepancy on the level of chi now includes Sergei Antipin, Leonid Berdnikov, Dmitry Bi- 2ϭ6.10 for all the analyzed data. We show that in HD zyaev, Yuri Dumin, Yuri Efremov, Andrew Fokin, Alex- 187474 the magnetic dipole is displaced from center of the ander Ipatov, Natalia Katysheva, Alexander Khoperskov, star by 0.055 Rstar. The dipole has a size ϳ0.035 Rstar. The Sergei Lamzin, Oleg Malkov, Alexey Mironov, Vladimir angle between the stellar rotational axis and the magnetic Obridko, Anatoly Piskunov, Sergei Popov, Nikolai Samus, ϭ dipole is beta 37degr. Sergei Shugarov, Vladislav Sidorenko, Olga Silchenko, Gre- L.M. Shulman propos three empirical equations to de- gory Tsarevsky, Boris Yudin ͑deceased on April 5, 2004͒, scribe the existing experimental data on the heat capacity of and Alexander Zakharov. The Resident Director of the INI р р water ice for 0 K T 273 K. This may be important for Branch is Nikolai Samus. the rate of non-stationary thermal processes at very low tem- In 2003–2004, Olga Sil’chenko selected and studied a peratures in cometary nuclei or cosmogonical scenarios sample of lenticular galaxies with polar dust lanes near the ͑ ͒ 2004, A&A, 416, 187-190 . nuclei. In all the galaxies, circumnuclear ionized gas rotates in planes nearly orthogonal to the stellar rotation planes, so 8. THE INI MOSCOW BRANCH all these galaxies are galaxies with ‘‘inner polar rings.’’ Cu- The Isaac Newton Institute opened its branch in Moscow riously, the nuclear stellar populations in these galaxies are, in June 1992. The formal Agreement was signed with Prof. on average, older than the mean age of the nuclear stellar A.A. Boyarchuk, at that time Director of the Institute of As- populations in S0 galaxies without inner polar rings. It can tronomy of Russian Academy of Sciences and the President be concluded that the inner polar rings are very stable over of the IAU, and Prof. Anatoly Cherepashchuk, Director of timescales of several billion years, and their gas never the Sternberg Astronomical Institute of Lomonosov Moscow reaches the nuclei. She also studied central stellar popula- University. tions in NGC 3623 and NGC 3627 – members of the famous The Institute of Astronomy was established as the Astro- Leo Triplet. Their properties appear to be quite different; in nomical Council of the USSR Academy of Sciences on De- particular, the ages differ strongly. It is an evidence for rather cember 20, 1936. Originally, the organization had mainly late assembly of the Leo Triplet, about 1 Gyr ago. coordination functions in the Soviet astronomy. After the Olga Sil’chenko’s studies ͑with co-authors͒ of external 2nd World War, it started its own scientific research. To- galaxies won the 2004 State Prize of Russia, one of the high- gether with the Sternberg Institute, the Astronomical Council est awards in Russia for acheivements in science, technol- participated in the work on the General Catalog of Variable ogy, and culture. Stars, on behalf of the IAU. The scientific activity of the Leonid Berdnikov continued his many-year studies of Astronomical Council considerably expanded after the Cepheids, including new photometry and investigations of launch of the first Sputnik, the Council became responsible period changes. The Cepheid SV Vulpeculae was demon- for observations of artificial satellites and their use for space strated to be in the second crossing of the instability strip on geodesy, geodynamics, and geophysics. Besides, it was en- the basis of its well-defined period decrease of Ϫ214.3 Ϫ gaged in basic research in the fields of physics and evolution Ϯ5.5syr 1. Recent arguments from its atmospheric abun- of stars, solar activity, physics of the Moon, stellar spectros- dance pattern that it is in the first crossing are not supported copy. In 1958, it established an observatory near Zvenigorod by the historical photometric data. Furthermore, an examina- ͑Moscow Region͒. In December 1990, the Astronomical tion of atmospheric abundance patterns for other Cepheids in Council, already being in fact a scientific institute for many advanced strip crossing modes suggests that the presence of years, was formally reorganized into the Institute of As- CNO-processed material in the atmspheres of intermediate- tronomy of the USSR Academy of Sciences ͑since 1991, the mass stars does not arise from red supergiant dredge-up Institute of Astronomy of Russian Academy of Sciences͒. phases but from meridional mixing during previous evolu- The Institute’s new Director appointed in 2003, Prof. B.M. tion as rapidly-rotating main-sequence B-type stars. Shustov, continues providing support to the activities of the Dmitry Bizyaev determined structral parameters for a Moscow Branch of the Isaac Newton Institute. sample of 11 edge-on spiral galaxies from photometric ob- The history of Sternberg Astronomical Institute begins as servations. It is found that the stellar disks of low surface early as in 1831, when the Moscow University established an brightness ͑LSB͒ galaxies are thinner than those of high sur- observatory in Presnya district of Moscow. The present name face brightness ͑HSB͒ ones. There is a clear correlation be- 14 ANNUAL REPORT tween the central surface brightness of the stellar disk and its ing that the upper limit of the optical depth (␶ϳ0.1) corre- vertical to radial scale ratio. The masses of spherical sub- sponds to the case where dark matter forms cosmologically systems ͑dark halo ϩ bulge͒ and the dark halo masses are distributed deflectors, observations of the X-ray variations of obtained for the sample galaxies based on the thickness of unlensed QSOs can be used for the estimation of the dark their stellar disks. The LSB galaxies tend to harbor more matter fraction of microlenses. massive spherical subsystems than the HSB objects, whereas no systematic difference in the dark halo masses between 9. THE INI ODESSA BRANCH LSB and HSB galaxies is found. At the same time, the in- The Isaac Newton Institute opened its Odessa Branch in ferred mass-to-luminosity ratio for the LSB disks appears to May 2000. The formal Agreement has been signed with Prof. be systematically higher than for HSB disks. Valentin Karetnikov, Director of the Astronomical Observa- Andrew Fokin was engaged in theoretical studies of stel- tory of Odessa National University. lar atmospheres and in pulsation-theory studies. In a study of The staff of the Isaac Newton Institute in Odessa in- radiative cooling of shocked gas in stellar atmospheres, it cludes: Sergey Andrievsky, Ivan Andronov, Kirill Antonyuk, was demonstrated for the first time that the cooling due to Alexej Baklanov, Stanislav Belik, Vladimir Bezdenezhnyi, iron lines was largely dominant over the hydrogen and he- Osman Chahrukhanov, Nikolaj Chernykh, Irina Cherny- lium continuum cooling. A hydrodynamic model was gener- shova, Lidia Chinarova, Nikolay Dorokhov, Tatyana Dor- ated for the high-amplitude Beta Cephei star BW Vulpecu- okhova, Irina Egorova, Lyudmila Glazunova, Vera Gopka, lae. The star’s spectral line profiles were calculated and Alexander Halevin, Sergey Kolesnikov, Sergey Korotin, compared with observations. This is the first satisfactory Valery Kovtyukh, Larisa Kudashkina, Vladislava Marsa- model of BW Vul, giving a good theory/observation agree- kova, Tamara Mishenina, Victor Nazarenko, Alexander ment. Notably, the model predicts two strong shock waves Pikhun, Vasilij Rumyantsev, Leonid Shakun, Fedor Sirotkin, per period, which explains the famous ‘‘standstill’’ on the Sergey Udovichenko, Igor Usenko, and Alexander Yush- velocity curve. On the base of a non-linear, self-consistent chenko. The Resident Director of the INI Branch is Valery hydrodynamical model for Delta Cephei, the conversion fac- Kovtyukh. tor between radial and pulsation velocity was studied, and its Odessa is a big city ͑with more than one million citizens͒ implication for the recently elaborated Interferometric situated on the Black Sea coast. Founded in the end of the Baade-Wesselink method for determination of distances was XVIII century Odessa is full of beautiful sightseeins and cul- investigated in detail. tural traditions. Many famous people lived here. Pushkin, Oleg Malkov finished his comparative study of radii for Mendeleev, Mechnikov and Korolev are among them. eclipsing binary components and single stars reported in de- Odessa is also a hometown for one of the greatest cosmolo- tail last year. gists of the XX century—George Gamow. Alexey Mironov and Nikolai Samus resumed photometric Odessa Astronomical Observatory ͑OAO͒ was established studies of stellar populations in globular clusters. They are on August 3, 1871 as a part of Novorossijsky ͑now-Odessa now engaged in final reductions and data evaluations for National͒ University. It was first headed by Prof. L.F. CCD photometry in the globular cluster NGC 6864 acquired Berkevich, a distinguished specialist in celestial mechanics. and initially reduced by INI collaborators in Chile ͑Franklin An exceptional instrument was acquired to perform astro- Alvarado et al.͒. metric observationsϪThe Meridian Circle made by famous Alexander Zakharov, with collaborators, considered con- Repsold’s company. Astrophysical research began in 1881 tribution of microlensing to the X-ray variability of high- with the advent of a new director-astrophysicist Prof. A.K. redshifted QSOs. Such an effect could be caused by stellar Kononovich. Under his directorship, the OAO was turned mass objects located in a bulge or/and in a halo of this quasar into a truly research institution equipped with the first-class as well as at cosmological distances between an observer and instruments. A.K.Kononovich was one of the Russian pio- a quasar. Microlensing caused by deflectors in our Galaxy neers in astrophysics. He conducted active research of the was not considered: it is well-known from recent MACHO, Sun, photometry of the Solar system small bodies, etc. Many EROS and OGLE observations that the corresponding opti- of his students became well known scientists such as A.P. cal depth for the Galactic halo and the Galactic bulge is Ganskij, A.S. Vasil’ev, R. Orbinskij, N.N. Donich and oth- Ϫ lower than 10 6. Cosmologically distributed gravitational ers. In 1912 a distiguished astronomer, later academic A.Ya. microlenses could be localized in galaxies ͑or even in bulges Orlov, initiated an astro-geophysical direction at OAO by or halos of gravitational macrolenses͒ or could be distributed studying the tidal deformations of the Earth and gravimetry. in a uniform way. Both cases of such distributions were ana- At that same time monitoring of variable stars began ͑G.A. lyzed. As a result, it was found that the optical depth for Lange, V.P. Zesessevitch, V.V. Sharonov͒. Prof. K.D. Pok- microlensing caused by stellar-mass objects was usually rovsky, who came after A.Ya. Orlov, continued to expand small for quasar bulge and quasar halo gravitational micro- the range of scientific research: comets, asteroids, double Ϫ lens distributions (␶ϳ10 4). On the other hand, the optical stars, photometry and spectroscopy of stars of different types depth for gravitational microlensing caused by cosmologi- were added to the list of activities of Odessa astronomers. cally distributed deflectors could be significant and could In 1945, a famous astronomer, talented organizer and reach 10Ϫ2Ϫ0.1 at zϾ2. This means that cosmologically popularisor of science, Prof. V.P. Zessevitch took the direc- distributed deflectors may contribute significantlly to the tors’ chair. His primary interest lay in variable stars. He con- X-ray variability of high-redshifted QSOs (zϾ2). Consider- ducted more than 200,000 observations of variable stars of ISAAC NEWTON INSTITUTE OF CHILE 15 various types, published more than 600 papers and mono- of mass transfer in different binary systems is being used for graphs. Just at the end of World War II the number of ob- quantitive study of morphology of gas streams and its obser- servatory staff was only 5 people, but steadily grew since vational manifestations. 1950. OAO occupied one of the first places in the USSR in Heavy elements in Stellar Atmospheres: Investigators: variable stars search as well as other fields. V.P. Zessevitch Alexander Yushchenko, Vera Gopka. The main aim of this initiated construction of several field observational stations group is the investigation of abundances of heavy and super- and later-mountain observatories on the Caucasus and Pam- heavy elements in the atmospheres of stars of different types. ire. Systematic observations on the 7-camera astrograph be- Determinations of evolutionary stages and ages of these stars gan, and at present OAO possesses a unique collection of sky using cosmochronology. Investigations of chemical evolu- negatives. Hundreds of papers on variable stars were made tion of the Galaxy. Investigations of surface inhomogeneities using this material. In 1993 the staff of OAO grew up to 150 in the atmospheres of B and A stars. Methods: High and scientists, considerably increased the spectrum of scientific superhigh resolution spectroscopy from UV to IR. research: physics and evolution of stars, physics of small Photometrical Investigations of Variable Stars: Inves- bodies of the Solar System, precise stellar photometry, etc. tigators: Sergey Udovichenko, Nikolay Dorokhov, Tatyana Contacts with foreign colleagues are largely extended. In- Dorokhova, Vladimir Bezdenezhnyi, and Alexander Yush- ternational conferences are held each year: dedicated to vari- chenko. The main aim of this group is photometrical and able stars and Gamow memorial conference. In 1999 an an- spectral investigations of RR Lyraes, delta Scutti and other nual summer schools for young scientists started to operate. types of variable stars. Special attention will be devoted to At present OAO is a modern research organization. Being RR Lyraes. Fourier analysis of photometric observations of involved in fruitful collaboration with Isaac Newton Institute RR Lyrae on the 15 years time interval perfomed in Odessa of Chile, Odessa Astronomical Observatory has significantly Observatory. risen the level of its scientific investigations in modern as- Gravitational Lensing: Investigators: Alexander Yush- trophysics. chenko, Nikolay Chernyh, Vasilij Rumyantsev, and Osman The investigators incorporated to the Isaac Newton Chahrukhanov. The main aim of this group is the investiga- Branch are actively working in the following six fields of tion of lensing properties of globular clusters. We predicted research: observational tests that can confirm the important role of Periodic and Aperiodic processes in stars: Investiga- lensing by globular clusters. It will help us to observe high- tors: Ivan Andronov, Larisa Kudashkina, Sergey Kolesnikov, redshift objects with middle class telescopes, investigations Alexander Halevin, Vladislava Marsakova, Lidia Chinarova, of weak gravitational lensing by galaxies on the observation and Kirill Antonyuk. The aim of the project is to elaborate of quasi-stellar objects. additional criteria for classification of variable stars of dif- Van den Bergh in 1958 was perhaps the first to provide a ferent types-cataclysmic ͑highly magnetized, polars, interme- strong theoretical argument that a metallicity gradient should diate polars, weakly magnetic positive and negative super- exist in the Galactic disc. During the following almost 50 humpers, nova-likes͒ based on the polarimetric observations years many observational studies were performed with the of these stars at a time resolution from seconds to years; intent of determining the gradient. Astronomers have ana- long-periodic on time scales from months to decades; to lyzed the spectra of B stars, late-type supergiants, old disk elaborate corresponding mathematical methods. Multisite giants, and H II regions, frequently producing rather contra- observational programs of polars. This group uses the obser- dictory results. According to some authors, a quite steep vations of artificial satellites. present-day metallicity gradient exists in the disc ͑from -0.05 Spectral investigations of different type stars: Investi- to -0.10 dex/kpc͒, but much lower gradient values have also gators: Sergey Andrievsky, Valery Kovtyukh, Tamara Mish- been reported, and even no dependence of the abundances enina, Sergey Korotin, Igor Usenko, Irina Chernyshova, and upon the galactocentric distances was found in several Irina Egorova. The aim of the project is the investigation of surveys. chemical composition of stars of intermediate masses on dif- Cepheid variables are favorable objects for the study of ferent stages of evolution: cepheids, nonvariable supergiants their chemical composition. Their high luminosity provides and their ancestors, B-stars of the Main Sequence and also the opportunity to reach stars at large distances which is metal-poor stars, blue stragglers and lambda Bootis type important for the study of galactic structure. Their luminosi- stars. Methods: high dispersion spectral observations from ties can be determined by their periods and colors; and their western observatories and Russian 6-m telescope. LTE and masses can be estimated from their periods. Using their ef- non-LTE analysis of chemical composition. fective temperatures and their surface gravities the appropi- Astroseismology of single and eclipsing binary stars: ate model may be found for the analysis of their spectra to Investigators: Victor Nazarenko and Lyudmila Glazunova. derive the chemical composition of their atmospheres. Studies of pulsating roAp, lambda Boo, delta Scutti and These improved data on the metallicity distribution in the eclipsing binary stars using the asteroseismic and numerical Galactic disc over the galactocentric distance range 10-15 hydrodynamical methods. Asteroseismic methods are based kpc support the existence of a discontinuity at Rgϭ11 kpc. on high-precision multisite photometry and high-resolution Such a discontinuity could be a consequence of the specific spectroscopic observations of roAp, lambda Boo and delta initial conditions of the Galaxy formation ͑thick and thin disc Scutti stars and also for precise determinations of mass trans- separation͒, and might have survived over the long-term pe- fer rates in eclipsing binaries. Hydrodynamical simulations riod if the mixing process smoothing the metallicity differ- 16 ANNUAL REPORT ences was not efficient in this particular region near Rgϭ11 important constraints to the construction of models of chemi- kpc. cal and dynamical evolution of our galactic system. T. Mish- These new observations of metal-poor outer disc Ceph- enina and co-authors ͑T. Mishenina, C. Soubiran, V. Kov- eids will also be very useful in an investigation of the me- tyukh, and S. Korotin, 2004͒ have performed the detailed tallicity dependence between Cepheid absolute magnitudes analysis of 174 high-resolution spectra of FGK dwarfs ob- and infrared surface brightnesses. tained with the ELODIE echelle spectrograph at the Obser- In 2004, V. Kovtyukh and S. Andrievsky together with G. vatoire de Haute-Provence. Abundances of Fe, Si and Ni Wallerstein ͑USA͒͑Kovtyukh et al., A&A 2004, submitted͒ have been determined from equivalent widths under LTE continued the investigation of the Galaxy abundance gradi- approximation, whereas abundances of Mg have been deter- ent. They have added data for 16 distant Cepheids that were mined under NLTE approximation using equivalent widths observed with the echelle spectrograph of the Apache Point of 4 lines and profiles of 5 lines. Spatial velocities with an 3.5-m telescope to improve the correlations of abundance accuracy better than 1 km/s, as well as orbits, have been parameters with pulsation period and distance from the ga- computed for all stars. They have been used to define 2 sub- lactic center Rg. The most interesting is the N/C ratio which samples kinematically representative of the thin disk and the is predicted to be enhanced by a factor of 4 when an evolv- thick disk in order to highlight their respective properties. A ing supergiant cools to Teff ϭ 4000 K and the outer convec- transition occurs at ͓Fe/H͔ϭ-0.3. Stars more metal-rich than tion zone reaches the depth at which CN processing has con- this value have a flat distribution with ZmaxϽ1 kpc. There verted C to N. A Gaussian distribution around value of exist stars in this metallicity regime which cannot belong to ͓N/C͔ϭ0.6 has been obtained, just as was predicted in pre- the thin disk because of their excentric orbits, neither to the vious works. Nine times as many stars show this enhanced thick disk because of their low scale height. Several thin disk ͓N/C͔ as show ͓N/C͔Ͻ0.2. The ratio of 9 mixed to unmixed stars are identified down to ͓Fe/H͔ϭ-0.80. Their Mg enrich- stars may be taken as the ratio of evolutionary time spent on ment is lower than thick disk stars with the same metallicity. the blue loop to the time spent on the first crossing through This data suggest that the star formation in the thick the instability strip. Only two of our stars show a Lithium disk stopped when the enrichment was ͓Fe/H͔ϭ-0.30, line, RX Aur and YZ Aur. For the others, including stars ͓Mg/Fe͔ϭϩ0.20, ͓Si/Fe͔ϭϩ0.17. A vertical gradient in with ͓N/C͔Ͻ0.2, Li is depleted from its original abundance ͓␣/Fe͔ may exist in the thick disk but should be confirmed to ϽlogN͑Li͒ϭ1.0 or somewhat less. Hence it appears that with a larger sample. Also have identified 2 new candidates mixing depletes Li before stars enter the instability strip. of the HR1614 moving group. Larger samples are necessary According to stellar models the main mixing event takes to confirm this findings on the thin disk and the thick disk. place when Teff drops below 4000 K, which is outside the Unfortunatly thick disk stars are quite rare in the solar neigh- red edge of the instability strip; i.e. after stars have crossed borhood and the construction of a significant sample of local the instability strip for the first time. Also RX Aur and YZ thick disk stars implies either a huge complete sample of Aur have broadened spectral lines of all elements. Altogether disk stars, among which 2% to 15% of thick disk stars are this could be a sign that these two Cepheids are crossing the expected, or the selection of such stars by kinematical or instability strip for the first time. RX Aur, YZ Aur and SV chemical criteria which bias the conclusions which can be Vul show the following common peculiarities: 1. The width drawn. A lot of observing material is available. Detailed of the spectral lines in RX Aur and YZ Aur are larger than in analysis of spectroscopic data is a tedious work that takes other Cepheids ͑rotation? macroturbulence? non-radial pul- much time to measure equivalent widths, to fit profiles, to sation?͒. But it should be noted that at the same time the compute models etc... Itisnow absolutly necessary to de- spectra SV Vul show sharp lines ͑maybe we see a polar velop automatic methods to take advantage of the huge region of SV Vul͒. 2. Pulsational period is about constant for amount of high quality data which is provided by the new RX Aur and YZ Aur or even decreasing ͑SV Vul͒, but the generation of spectrographs. evolutionary calculations predict a rapid increase of period Main sequence stars are by far the most numerous type of for the first-crossing Cepheids. The high-temperature bound- stars in the Universe. They are often somewhat neglected as ary of the instability strip for the first crossing Cepheids is they are relatively quiet objects ͑but exceptions exist͒, de- shifted approximately 200 K towards the higher tempera- spite that they bear testimony of the past and future of our tures. This means that RX Aur, YZ Aur and SV Vul lie Sun. An important characteristic of these stars, particularly outside the classical instability strip for the usual fundamen- the solar-type ones, is that they host the large majority of the tal pulsators. Therefore, they are moving to the instability known extrasolar planets. And at the bottom of the main strip region from the main-sequence stage. For these stars the sequence, the FGK dwarfs pave the way to our understand- Li is somewhat less depleted than for the vast majority of ing of the physics of the stars. Highly precise temperatures Cepheids. However their ͓N/C͔ values fall within the group ͑sigma ϭ 10-15 K͒ have been determined from line depth of stars that show clear evidence of the classical first dredge- ratios for a set of 248 F-K field dwarfs of about solar metal- up. Also confirmed previously known correlations of ͓Fe/H͔ licity, based on high resolution ͑Rϭ42000͒, high S/N echelle with Rg. The only other significant gradient is that of ͓Eu/Fe͔ spectra ͑V. Kovtyukh, C. Soubiran, and S. Belik, A&A ac- which increases with Rg thereby showing an increasing ratio cepted, 2004͒. A new gap has been discovered in the distri- of SNII/SNIa in the outer Galaxy. bution of stars on the Main Sequence in the temperature The behavior of stellar elemental abundances with age range 5560 to 5610 K. This gap coincides with a jump in the and kinematics, in various substructures of the Galaxy, puts microturbulent velocity and the well-known Li depression ISAAC NEWTON INSTITUTE OF CHILE 17 near 5600 K in field dwarfs and open clusters. The dwarfs the same manner as done here and in paper I. The shorter located on the left of the blue side of the gap show a large period Cepheids could well show a different behavior as the spread in lithium abundance, with values A͑Li͒ ranging from faster pulsation could lead to more pronounced hydrody- less than 1.0 to 3.0 dex. In contrast, stars located on the right namic phenomena. Additionally, in the shorter period Ceph- of red side show low values of A͑Li͒,reflecting the dilution eids one must deal with the question of overtone versus fun- effects in this spectral region. It is clear that the sudden de- damental pulsation modes and how that relates to the cline in A͑Li͒ near the temperature gap is directly associated reliability of derived parameters. After this is done, authors with a rapid increase in thickness of the convective envelope hopefully will be able to come to stronger conclusions con- in such regions. Most of the stars with high Li abundance cerning the properties of Cepheids; especially in relation to present an undeveloped convective zone, whereas stars with dealing with questions 2 and 3 which were posed in this low Li abundance show a developed convective zone. As the paper. Also sample size ͑i.e., mass/period range͒ is not yet principal cause of the observed discontinuities in stellar large enough to warrant dealing with questions of reddening properties the authors propose the penetration of the convec- and especially relations between mass and observed tive zone into the inner layers of stars slightly less massive behavior. than the Sun and related to it, a change in the temperature gradient. Kovtyukh and co-authors ͑Kovtyukh et al., AnJ submited, 10. THE INI PETERSBURG BRANCH ͒ 2004 carried out a detailed multiphase spectroscopic analy- The Isaac Newton Institute opened its St. Petersburg sis of 14 classical Cepheids with pulsation periods longer Branch in September 2000. The formal Agreement has been than 10 days. For each star derived phased values of effec- signed with Prof. Veniamin Vityazev, Director of the Astro- tive temperature, surface gravity, microturbulent velocity, nomical Institute of St. Petersburg State University in Rus- and elemental abundances. The main result is that the el- sia. The staff members belong to all major astronomical cen- emental abundance results for these Cepheids are consistent ters in St. Petersburg, such as the Pulkovo Observatory, the for all pulsational phases. This is the second in a series of Institute of Applied Astronomy, and Ioffe Physico-Technical papers in which authors consider multiphase properties of Institute. classical Cepheid variables. Specifically, authors consider The staff of the Isaac Newton Institute in St. Petersburg the atmospheric parameters: effective temperature, surface are: Ekaterina Aleshkina, Anisa Bajkova, Yurij Baryshev, gravity, and microturbulence and from them were derived Nina Beskrovnaya, Yulia Chernetenko, Alexander Gromov, the chemical composition of the program stars at a range of Vladimir Hagen-Thorn, Nazar Ikhsanov, Vladimir Il’in, phases spread over the pulsational cycle. The first paper of Vsevolod Ivanov, Tamara Ivanova, Gulnara Karataeva, Al- this series considered intermediate period Cepheids; i.e., exander Kholtygin, Denis Konenkov, Iraida Kozlova, Valeri those with periods from 6 to 10 days. The importance of the Larionov, Dmitrij Nagirner, Leonid Parfinenko, Elena role of Cepheid variable stars in the investigation of various Pitjeva, Mikhail Pogodin, Alexander Potekhin, Vladimir problems of cosmology, galactic chemodynamics, and stellar Reshetnikov, Yuriy Rusinov, Elena Skurikhina, Nikolay physics is difficult to overestimate. Nevertheless, one par- Sokolov, Michail Sveshnikov, Vadim Urpin, Olga ticular aspect of the Cepheids is not well elaborated at this Vasilkova, Nikolai Voshchinnikov, Eleonora Yagudina, time. This is the characteristics of variation of Cepheid fun- Valeria Yakovleva and Ruslan Yudin. The Resident Director damental ͑atmospheric͒ parameters over the pulsation cycle, of the INI Branch is Vladimir Reshetnikov. and the possible impact of those variations on the derived The Astronomical Institute of Petersburg State University elemental abundances. Such an analysis should be capable of is one of the best known astronomical organizations in Rus- answering a number of important questions relative to our sia. It was established in 1881 as Astronomical Observatory understanding of Cepheids and thus help to determine the at the Chair of Astronomy of St. Petersburg University ͑the reliability of our analyses. Three of these problems are: ͑1͒ Chair was orgzanized in 1819͒. Since 1999 it is entitled as The problem of consistency of the derived elemental abun- Sobolev Astronomical Institute. The staff of the Institute in- dances at different phases over the pulsational cycle. ͑2͒ The clude about 60 scientists. The main fields of research are problem of the gravity and microturbulence variation over cosmology, observations of active galaxies and variable the pulsational cycle, and the possibility of the dependence stars, physics and evolution of stars, solar physics, dynamics of the amplitude of such variations upon Cepheid character- of gravity systems, celestial mechanics, astrometry, cosmic istics such as mass, luminosity, and period. Such a depen- hydrodynamics, theory of radiation transfer, light scattering dence; if present, could serve as an additional test for hydro- theory, astrospectroscopy and development of special astro- dynamic models of Cepheids. ͑3͒ And finally, the problem of nomical software. reddening and distances. Since our spectroscopic analysis al- The Main Astronomical Observatory ͑Pulkovo Observa- lows one to determine for each star the reddening-free value tory͒ opened in 1839 was the first astronomical institution in of the effective temperature, this immediately affords the Russia. For a long time, it was the principal observatory in possibility of performing an independent evaluation of pho- Russia and USSR. The current staff of the observatory con- tometric based reddening values. These problems will be sist of 160 scientists. The research areas are radioastronomy, best considered when the complete range of Cepheids peri- physics of galactic nuclei, X-ray sources and young stars, ods has been covered. Our last target in this series of papers solar physics, solar-terrestrial relations, celestial mechanics will be to investigate shorter period ͑PϽ6 days͒ Cepheids in and stellar dynamics, astrometry, geophysics, development 18 ANNUAL REPORT of astronomical methods and construction of optical devices. that the mass transfer in this system operates via the Roche The observatory also develops cosmic projects such as: lobe overflow mechanism, but the material transferred from ‘‘Struve,’’ ‘‘Geobs,’’ and ‘‘Stereoscope.’’ the normal companion is neither accreted onto the surface of The Institute of Applied Astronomy was founded in 1987 the white dwarf nor stored in a disk around its magneto- due to the decree of the Academy of Science of USSR for sphere. As previously shown, such a situation can be realized realization of the biggest national astronomical project- if the white dwarf operates as a propeller. At the same time, establishment of the very long baseline radio interferometri- the efficiency of the propeller action by the white dwarf is cal network ‘‘QUASAR.’’ Over 130 scientists work in the insufficient to explain the rapid braking of the white dwarf, Institute. Main field of research are in radioastronomy, rela- which implies that the spin-down power is in excess of the tivistic celestial mechanics, radioastrometry, ephemerides as- bolometric luminosity of the system. To avoid this problem tronomy, cosmic geodesy, geodynamics, development of as- they have simulated the mass-transfer process in AE Aqr tronomical software, data processing methods, creation of assuming that the observed braking of the white dwarf is hardware for radioastronomy. governed by a pulsar-like spin-down mechanism. They show The Ioffe Institute is one of Russia’s largest institutions that the expected H Doppler tomogram in this case resembles for research in physics and technology with a wide variety of the tomogram observed from the system. Ikhsanov, Neus- operating projects. It was founded in 1918 and run for sev- troev, & Beskrovnaya find that the agreement between the eral decades by Abram F. Ioffe. So it is quite natural that the simulated and the observed tomograms is rather good pro- Institute bears the name of this outstanding scholar and vided the mean value of the mass-transfer rate of 5 1016 g/s. organizer. Three spatially separated sources of H emission can be dis- Beskrovnaya & Pogodin ͑2004, A&A, 414, 955͒ de- tinguished within this approach. The structure of the tomo- scribed the results of observations of the Herbig Ae star HD gram depends on the relative contributions of these sources 31648 including high-resolution spectroscopy near the H, He to the H emission and is expected to vary from night to night. I 5876 and DNa I lines, multi-color photometry and polar- The appearance of subsonic propellers situated in a strong imetry. These observations have revealed many features of wind is discussed by Ikhsanov & Choi ͑2004, A&A, 423, the observational appearance of HD 31648 similar to those 1023͒. The model predicts the existence of at least two spa- of the ‘‘classical’’ Herbig Ae stars. Among them are spectral tially separated sources of the X-ray emission: hot spots at manifestations of both the mass loss and the disk accretion the stellar surface, and the hot atmosphere surrounding the onto the star and certain types of line profile variations. The magnetosphere of the star. The ages of the subsonic propel- totality of the observed properties of HD 31648 provides lers under the conditions of interest are limited to ϳ105 yr. evidence in favor of complicated structure in the stellar wind Karataeva et al. ͑2004, A&A, 421, 833; AJ, 127, 789͒ zone, exhibiting latitudinal stratification and containing loin- present the results of stellar photometry of the polar-ring homogeneities in the form of outflowing streams and density galaxies NGC 660, NGC 2685 and NGC 4650A using the condensations. Structural variations of the stellar wind have Hubble Space Telescope’s archival data obtained with the been found to correlate with changes in the accretion process Wide Field Planetary Camera 2. The analysis of the Colour- in the envelope. The circumstellar environment of HD 31648 Magnitude Diagram for polar ring stars shows that it is best is supposed to contain dust particles of different forms mani- represented by the isochrones with metallicity Z ϭ 0.008. festing themselves, in particular, in the variable multi- The process of star formation in the polar rings of all galax- component intrinsic polarization ies was continuous, and the age of the youngest detected Hagen-Thorn and Larionov are participiants of a large stars is about 7 Myr for NGC 660, 9 Myr for NGC 2685 and international collaboration on blazar BL Lacertae ͑2004, 6.5 Myr for NGC 4650A. A&A, 421, 103; A&A, 424, 497͒. The results of high-resolution spectroscopy of the Herbig Gromov, Baryshev & Teerikorpi ͑2004, A&A, 415, 813͒ Be star HD 200775 obtained within the framework of a co- developed a new classification of two fluid FLRW cosmo- operative observing programme in 2000-2002 are presented logical models with interacting dark energy and matter com- by Pogodin et al. ͑2004, A&A, 417, 715͒. A new high- ponents. The behavior of the energy content, gravitating activity phase of the object’s H line occurred in the middle of mass, pressure, and energy transfer between dark energy and 2001 in full agreement with a 3.68-year periodicity predicted dark matter cosmological fluids, were given as functions of earlier. A complicated picture of the H line profile variability the scale factor for different two-fluid classes, defined by the near the activity maximum phase turned out to be very simi- presence or absence of energy exchanging and by the station- lar to that observed during the previous one in 1997. Varia- ary or non-stationary of the equation of state. Three charac- tions of the radial velocity with the activity phase are de- teristic scales were found which separate periods of time tected in He I, Si II, and S II photospheric lines. The when quintessence energy, pressure and gravitating mass observed phenomena are interpreted in the framework of a dominate. This study is a necessary step in constructing ob- model in which the star, together with its gaseous envelope, servational tests of cosmological models for which a phe- is a component of an eccentric binary system. A preliminary nomenological description of dark energy - matter conver- orbital solution is derived, and the system’s parameters are sion may be done. estimated from the radial velocity curves of the H emission Ikhsanov, Neustroev, & Beskrovnaya ͑2004, A&A, 421, line. Pogodin et al. find that the orbital eccentricity is e 0.3, 1131͒ investigated the mass transfer process in AE Aquarii. the mean companion separation is 1000 R᭪ , and the second- The observed properties of the close binary AE Aqr indicate ary companion is most likely to be a 3.5 M᭪ pre-main se- ISAAC NEWTON INSTITUTE OF CHILE 19 quence object. They emphasize the importance of coordi- angular momentum profile, while unstable modes with wave- nated spectroscopic and interferometric observations at vectors perpendicular to the axis remain unaltered. Since the different phases of the object’s activity for further under- wave-vector is perpendicular to the velocity perturbation, the standing the properties of the system. directional selection of the unstable modes may result in Potekhin et al. ͑2004, ApJ, 612, 1034͒ studied polariza- fluid motions along the direction of the rotation axis. This tion properties of partially ionized hydrogen plasmas in occurs in rigidly rotating stars as well as in the inner core of strong magnetic fields and used the obtained polarizability differentially rotating stars. The asymmetric convective tensor to construct atmosphere models for magnetized neu- transport of energy and angular momentum can be the seed tron stars in radiative equilibrium. In this study, they used of anisotropies at large scale, that in combination with other the equation of state and absorption coefficients of partially effects such as anisotropic accretion of matter, rotational in- ionized H plasmas obtained by Potekhin and Chabrier for the duced non–radial oscillations, or the magnetorotational in- magnetic field strengths typical for pulsars ͑2003, ApJ, 585, stability, could be the key of successful Supernovae explo- 955͒ and magnetars ͑2004, ApJ, 600, 317͒. sions. The results of this work provide a natural source of Yakovlev, Levenfish, Potekhin, Gnedin, & Chabrier asymmetry for proto–neutron stars with the only requirement ͑2004, A&A, 417, 169͒ calculated the thermal structure and that angular velocities be of the order of the convective char- quiescent thermal luminosity of accreting neutron stars acteristic frequency. ͑warmed by deep crustal heating in accreted matter͒ in soft Stability of the ocean of magnetic neutron stars has been ͑ ͒ X-ray transients ͑SXTs͒. They considered neutron stars with considered by Urpin 2004, A&A, 421, L5 . It has been ar- nucleon and hyperon cores and with accreted envelopes and gued that the ocean is unstable if the temperature varies compared the obtained theoretical results with observations along the surface. The instability grows on a time scale ϳ Ϫ of SXTs, particularly, containing the coldest ͑SAX J1808.4- 0.1 100 s depending on the lengthscale of perturbations 3658͒ and the hottest ͑Aql X-1͒ neutron stars. They showed and generates a weak turbulence. Turbulence can be respon- that observations of SAX J1808.4-3658 in a quiescent state sible for mixing between the surface and deep ocean layers can be explained only if this SXT contains a massive neutron and can enhance heat transport in the surface region. ͑ star with a nucleon/hyperon core; a hyperon core with a not Voshchinnikov, Il’in & Henning A&A, in press, astro- ͒ too low fraction of electrons is preferable. ph/0409457 investigate different methods to describe light Haensel & Potekhin derived analytical representations for scattering by composite particles. Both a model of layered two unified equations of state of neutron-star matter: FPS particles and discrete dipole calculations for particles with and SLy. These representations are useful for 2-D calcula- Rayleigh and non-Rayleigh inclusions are used. The calcula- tions of stationary rotating configurations of neutron stars tions demonstrate that porosity is a key parameter for deter- ͑A&A, in press, astro-ph/0408324͒. mining light scattering. They find that the optical properties Reshetnikov ͑2004, A&A, 416, 889; A&A, in press͒ pre- of the layered particles depend on the number and position of sented results of B,V,R surface photometry of five polar-ring layers if the number of layers is small. For a larger number galaxies ͑PRGs͒ and related objects – A0017 ϩ2212, of layers the scattering characteristics become independent UGC1198, UGC4385, AM1934 -563, ESO474 -G26. It was of the layer sequence. The optical properties of particles with shown that all the galaxies are peculiar late-type spirals in inclusions depend on the size of inclusions provided the po- the state of ongoing interaction or merging. He discussed rosity is large. The scattering characteristics of very porous possible origins of the objects and presented numerical simu- particles with inclusions of different sizes are found to be lations to study its possible formation mechanisms. close to those of multi-layered spheres. They compare the results of these calculations with the predictions of the effec- Urpin & Gill ͑2004, A&A, 415, 305͒ considered genera- tive medium theories ͑EMT͒ which are often used in as- tion and evolution of small-scale magnetic fields in neutron tronomy as a tool to calculate the optical properties of com- stars. These fields can be generated by small-scale turbulent posite particles. The results of the analysis show that the dynamo action soon after the collapse when the proto- internal structure of grains ͑layers versus inclusions͒ only neutron star is subject to convective and neutron finger in- slightly affects the optics of particles provided the porosity stabilities. After instabilities stop, small-scale fields should does not exceed 50%. It is also demonstrated that in this case be frozen into the crust that forms initially at high density the optical properties of composite grains calculated with ϳ1014 g/cm3 and then spreads to the surface. Because of EMT agree with the results of the exact method for layered high crustal conductivity, magnetic fields with the length- particles. For larger porosity, the standard EMT rules ͑i.e., scale ϳ1Ϫ3 km can survive in the crust as long as 10-100 Garnett and Bruggeman rules͒ give reliable results for par- Myr and form a sunspot-like structure at the surface of ticles with Rayleigh inclusions only. radiopulsars. Miralles, Pons & Urpin ͑2004, A&A, 420, 245͒ studied the conditions for convective instability in rotating, non- 11. THE INI POLISH BRANCH magnetic proto–neutron stars. The criteria that determine The Isaac Newton Institute opened its Branch in Poland in stability of nascent neutron stars are analogous to the May 2001. The formal Agreement has been signed with Prof. Solberg–Ho”iland conditions but including the presence of Janusz Gil, Director of the Kepler Astronomical Center of lepton gradients. Our results show that, for standard angular Zielona Gora and Resident Director Prof. Andrzej Maciejew- velocity profiles, convectively unstable modes with wave- ski in charge of inviting a group of selected astronomers vectors parallel to the rotation axis are suppressed by a stable from main Polish Astronomical Organizations. Among these 20 ANNUAL REPORT centers are the Warsaw University Observatory, Nicolaus Sergei Kutuzov, Arkady Kuzmin, Boris Losovsky, Valerij Copernicus Astronomical Centre, Turun Centre for As- Malofeev, Igor Malov, Oleg Malov, Vladimir Potapov, Al- tronomy and Astronomical Units from Universities. exey Pynzar’, Alexander Rodin, Vladimir Shishov, Vladimir The staff of the Isaac Newton Institute in Poland are: Shoutenkov, Grigori Smirnov, Tatiana Smirnova, Svetlana Krzysztof Belczynski, Slawomir Breiter, Janusz Gil, Krzysz- Souleimanova, Alexander Tsivilev, Sergei Tyul’bashev, and tof Gozdriewski, Tomasz Kwiatkowski, David Khechinash- Eduard Vitrichenko. The Resident Director of the INI vili, Jacek Kreiowski, Andrzej Maciejewski, George Me- Branch is Igor Malov. likidze, Maciej Mikolajewski, Michal Ostrowski, Krzysztof Observations of the recently detected ͑Kuzmin, Ershov & Rochowicz and Toma Tomov. The Resident Director of the Losovsky, Astronomy Letters, 2004, v.30, p.247͒ giant INI Branch is Andrzej Maciejewski. pulses ͑GPs͒ from the pulsar PSR B0031-07 were carried out This Branch was established following the suggestion of at 40 and 111 MHz. At 40 MHz the peak flux density of the Prof. Andrzej Maciejewski, in his position as Chair of the strongest pulse is 1100 Jy, which is 400 times as high as the Department of Astronomy and Astrophysics of Torun Centre peak flux density of the average pulse ͑AP͒. A pulse whose of Astronomy. This organization is a part of the Faculty of observed peak flux exceeded the peak of the AP by more Physics and Astronomy of the Nicolaus Copernicus Univer- than a factor of 200 is encountered approximately once in sity, created in 1997 by a union of Torun Radio Astronomy 800 observed periods. Peak flux density of the GPs com- Observatory and the Institute of Astronomy. pared to the AP peak flux density SGPpeak /SAPpeak has The Nicholas Copernicus University in Torun set up in roughly a power-law distribution with a slope of -4.5. GPs at 1945, is the biggest university in Northern Poland and out- 40 MHz are essentially stronger than those ones at 111 MHz. standing in terms of scientific potential. Torun is one of the This excess is approximately in inverse proportion to the oldest and, in the past, one of the richest cities in Poland, frequency ratio. The giant pulses are much narrower than the lying on the river Vistula, about 200 km north-west of AP, and cluster in two narrow regions of the AP near the Warzaw. peaks of the two components of the AP. Some of the GPs emit at both phases and are double. The separation of the 12. THE INI PUSHCHINO BRANCH double GP emission regions depends on frequency. Similarly The Isaac Newton Institute opened its Branch in Push- to the frequency dependence of the width of the AP, it is less chino in May 2002. The formal Agreement was signed with at 111 MHz than at 40 MHz. This suggests that GPs are Prof. R. D. Dagkesamanskii, Director of the Pushchino Ra- emitted from the same region of the magnetosphere as the dio Astronomy Observatory, Astro Space Center of the Leb- AP, that is in a hollow cone over the polar cap instead of the edev Physical Institute of the Russian Academy of Sciences. light cylinder region. Pushchino Radio Astronomy Observatory was established PSR B0031-07 as well as the previously detected PSR as the Radio Astronomy Station in 1956 and became one of B1112ϩ50 are the first pulsars with GPs that do not have a the greatest radio astronomical centers in the world. Three high magnetic field at the light cylinder. One may suggest radio telescopes operate here up to now. that there are two classes of GPs, one associated with high- The first of them RT-22, the parabolic reflector with its energy emission from outer gaps, the other associated with main dish of 22 m in diameter, was constructed in 1959 for polar radio emission. The GPs of PSR B0031-07 and PSR investigations of the interstellar medium, planets, and dis- B1112ϩ50 are of the second class. The dispersion measure Ϫ3 crete radio sources in the centimeter and millimeter ranges. DM is found to be 10.890Ϯ0.003 pcϫcm ͑A.D. Kuzmin, The first line of excited hydrogen H90Ϫ␣ was discovered A.A. Ershov, and B.Ya. Losobsky͒ with this telescope in 1964. The second instrument DKR- As is presently expected the partially ionized local inter- 1000, the meridian telescope consisting of 2 arms ͑East-West stellar medium before interacting with the heliospheric and North-South͒, began to operate in 1964. The main prob- plasma on the upwind side most probably undergoes an outer lems for this telescope were spectra of discrete sources and bow shock and after conversion into a submagnetosonic dynamics of the interplanetary plasma. Since 1968 many pul- plasma flow passes around the heliopause. While the ionized sars were observed by using DKR-1000. The third radio tele- component there undergoes abrupt changes in its dynamical scope BSA, the phased array comprising 16384 dipoles, was properties, the neutral component first continues to flow constructed in 1974 and was intended for investigations of downstream of the shock with its unperturbed properties. As pulsars at frequency 102.5 MHz. Since 1999 BSA operates at a consequence the two fluids immediately after the bow 111 MHz. This reconstruction was caused by strong interfer- shock passage are out of dynamical and thermodynamical ences at 102 MHz. Several new pulsars were discovered with equilibrium, i.e. neutral atoms move with a higher bulk ve- BSA, and more than 300 known pulsars were investigated by locity and are cooler than the ions. Due to intensive local using this antenna. Moreover it gives the possibility to study charge-exchange couplings between neutral atoms and pro- the interplanetary and interstellar media, many distant galax- tons these different properties tend to mix each other via ies and quasars and the structure of the Universe. BSA is the momentum- and energy exchanges. It turns out that the most sensitive telescope in the world in the meter wave charge exchange period is shorter than the relaxation period. range up to now. Hence the distribution functions cannot relax rapidly enough The staff of the Isaac Newton Institute Pushchino Branch to their highest-entropy forms, i.e. shifted Maxwellians. Here includes now Vadim Artyukh, Igor Chashey, Alexander Er- we study the transport processes of newly injected ions in shov, Valeriy Frolov, Alexander Glushak, Vera Izvekova, velocity space considering their quasi-linear and non-linear ISAAC NEWTON INSTITUTE OF CHILE 21 interactions with the ambient MHD turbulence in the plasma Gamma-Repeaters ͑SGRs͒ with drift waves near the light interface region. For that purpose the turbulence levels in the cylinder of a neutron star, rotation periods P, their deriva- heliosheath plasma region are studied. The expected devia- tives dP/dt and magnetic fields B in the regions of generation tions from equilibrium distributions of ionic and atomic spe- of emission observed in these objects are calculated. The cies in the outer heliospheric interface are calculated. It intervals for these parameters are clearly turns out from these studies that non-relaxed non- P ϭ 11 - 737 msec, dP/dt ϭ 3.7ϫ1016 - 5.5ϫ1012, log B equilibrium distribution functions have to be expected both ϭ 2.63 - 6.25. A strong relationship between the pulsed for OϪ /HϪ ions and atoms in this region with all the inher- X-ray luminosity L of AXP and SGR and the rate of their ent implications for the diagnostics of interstellar parameters rotation energy losses dE/dt is detected. It coincides with the deduced from observations made further inwards from the dependence Lx ͑dE/dt͒ for radio pulsars with detected X-ray interface region ͑I. Chashey͒. radiation. Slopes of the relationships log ͑dP/dt͒ - logP and The data of Anomalous X-ray Pulsar ͑AXP͒ 1E2259 log ETA -logP for AXPs and SGRs and for radio pulsars ϩ586 and AXP candidate 1RXS J1308.6ϩ212708 observa- with short periods (PϽ0.1sec) are equal each other (ETA is tions at the frequencies 111, 87 and 61 MHz are reported. the efficiency of a transformation of the rotation energy into The observations were carried out with two sensitive radio radiation͒. Magnetic fields at the neutron star surface calcu- telescopes of PRAO ASC FIAN. The mean profiles, the es- lated in the framework of the dipole model for AXPs and timations of the dispersion measure and the distance to the SGRs have the same order (ϽlogBsϾϭ11.90) as for nor- both objects are presented as well as the estimations of the mal radio pulsars ͑I. Malov͒. spectral index and the integral luminosity. The comparison It is shown that cyclotron radiation of electrons near the of our data with the X-ray data showed the presence of large surface of a neutron star with magnetic field ϳ1012G gives difference in the width of mean pulses and the luminosities. the possibility to explain the observed quiescent X-ray emis- The detection of AXPs radio emission together with another sion of AXPs and SGRs. The pulsed emission is generated data gives the reason to revise either the radio emission by the synchrotron mechanism near the light cylinder. Cata- mechanisms in the ‘‘magnetar’’ model or the ‘‘magnetar’’ clysms on the neutron star can cause short gamma-ray bursts model itself ͑V. Malofeev, O. Malov, and S. Tyul’bashev͒. with a power more than the X-ray power 22⌫ times. Here ⌫ Interplanetary scintillation observations of 48 flat spec- is the Lorentz-factor of emitting electrons. It is shown that in trum radio sources have been carried out at ϳ111MHz using the ‘‘magnetar’’ model the electron cyclotron line with the the interplanetary scintillation method on the Large Phased energy ϳ1MeV must be formed. Its detection will be a good Array ͑BSA͒, Russia. It gave the possibility to estimate the evidence for this model ͑I. Malov͒. flux densities of 13 sources, getting upper limits for the re- The longitude separation between adjacent drifting sub- maining 35. Gathering more or improving VLBI data on pulses is roughly constant for many pulsars. It was than per- these sources might significantly improve our results. This plexing when pulsar B0809ϩ74 was found to exhibit sub- proof-of-concept project tells us that, surprisingly, compact stantial variations in this measure, both with wavelength and (Ͻ1Љ) flat spectrum radio sources show strong enough scin- with longitude position within the pulse window. These tillations at ϳ111MHz to establish/constrain their spectra variations between 40 and 1400 MHz are analyzed. It is ͑low-frequency end͒͑s. Tyul’bashev͒. shown that they are caused primarily by the incoherent su- The integrated radio luminosities L for 311 normal pul- perposition of the two orthogonal modes of polarization ͑S. sars and for 27 ones with the rotation period PϽ0.1s Souleimanova͒. ͑‘‘fast’’ pulsars͒ were calculated using new data on their The physical conditions in nuclei of radio galaxies 3C 111 compilated spectra. The values of L lie in the interval be- and 3C 465 have been investigated. It is shown that the mag- tween 1027 and 1030 erg/s for 88 % of the normal pulsars and netic field strengths in central regions of the nuclei at the in the range 1028 -1031 erg/s for 88 % of the fast objects. The scale ϳ0.1pc are 3-4 order higher than the mean value and high correlation between L and estimates lϭSϫd2 from the they lie in the range 102ϽHϽ104 G ͑V. Artyukh and S. known catalogs are detected. It is shown that the coefficient Tyul’bashev͒. K of a transformation of the neutron star rotation energy into The complex analysis of four brightest stars of Orion Tra- radio emission increases when P grows for normal pulsars pezium is executed. The observations with participation of and falls for fast ones. The mean values of K are -3.73 and the author and the observations taken from the literature are -4.85 for normal and fast pulsars, respectively. There are no analyzed. changes of L with the kinematic age t ϭ z/v, where z is the The radial velocities of BM Ori star have been measured pulsar height over the Galactic plane and v ϭ 300 km/s is its using the spectra obtained using HST, IUE and BTA tele- mean velocity. The correlation between L and the rate of the scopes. The analysis shows that these velocities reveal epi- rotation energy losses E is detected for both pulsar groups sodic shift at 20-30 km/s. It may means that there is a third under consideration. In is shown that LϭAϫE1/3 for the star. New observations permit to improve the spectroscopic whole sample. The total number of pulsars in the Galaxy elements of close binary system and to estimate the possible (3ϫ105) and their birth rate ͑one per 35 years͒ are in agree- orbit of the third body. Preliminary elements are: Ep ϭ JD ment with data on the rate of supernova explosions ͑Malov 2444744, P ϭ 1302d, g ϭ 11 km/s, e ϭ 0.92, K ϭ 20 km/s, I., Malov O.͒ w ϭ 1.6 rad. In the framework of the model which connects X-ray The abundance of helium and iron in an atmosphere of the pulses of Anomalous X-ray Pulsars ͑AXPs͒ and Soft of BM Ori primary is appreciated. The spectra received with 22 ANNUAL REPORT

BTA telescope and taken from archives of IUE and HST At present SAO is the only Russian center for ground- satellites have been used. This star has the helium abundance based observations of the Universe. In Russia the observa- close to the solar one, but has no iron. The abundance of tory furnishes 80 percent of observational data in the field of helium and iron of other stars of Orion Trapezium is in gen- optical and radio astronomy. The telescopes BTA and eral similar to abundance of BM Ori primary, but there are RATAN-600 have the common use status allowing a broad some differences. For example, stars Ori C and Ori D have integration with the world astronomical community. Re- different mark of helium abundance with respect to the Sun, search activity in SAO is conducted by 110 researchers in 15 and BM Ori secondary has the normal abundance of iron. groups. The investigators incorporated to the Isaac Newton Two new components of BM Ori system was discovered Branch are working in the following fields: using the radial velocities measurements. The periods are 66 The Laboratory ‘‘Structure’’ performs the CCD photom- days and 120 years. etry and the spectroscopic study of Blue Compact Galaxies The new component of BM Ori is discovered by the cross ͑BCG͒ from the First Byurakan Survey. The main goal of the correlation method. The parameters of the component are the project is the investigation of the spatial distribution of low- following: Teff ϭ 4000 K, c R ϭ 16 R, M ϭ 1.8 M, K7 III, mass galaxies and modeling of the formation of the large m Mbϭϩ4. 0, Vsini ϭ 85 km/s, relative luminosity in V band scale structure of the Universe. Many new emission-line and is equal to 0.005 ͑ Vitrichenko E.͒ blue compact galaxies were discovered with the 6-m The spectra of BM Ori show absorption lines of Si IV and telescope. C IV ions, shifted at -69 km/s with respect to photospheric The Stellar Spectroscopy Laboratory studies the chemical lines. These lines do not change their position with phase of composition and the evolution of the stellar population in our orbital motion. The lines do not belong to stellar wind. It is Galaxy. The main attention is devoted to objects on the latest possible that these lines originate in ionized gas cloud which stages of stellar evolution. exists on line of sight. Other Orion Trapezium stars do not The Gamma Burst Study Group performs the CCD pho- ͑ ͒ show such absorption E. Vitrichenko and I. Malov . tometry of optical afterglows of gamma ray bursts and their host galaxies using the standart Johnson photometric system. From the comparison of the spectral energy distribution in 13. THE INI SAO BRANCH nearby galaxies and the observed afterglows photometry the The Isaac Newton Institute opened its SAO Branch in researchers define probable types of parent galaxies. May 2000. The formal Agreement has been signed with Prof. Main aims of the Laboratory of Relativistic Astrophysics Yuri Balega, Director of the Special Astrophysical Observa- are focused on studying the energy transformation mecha- tory ͑SAO͒ in Russia. nisms taking place in strong gravitational and magnetic The staff of the Isaac Newton Institute in SAO are: Irina fields. These fields are assosiated with nonstationar processes Acharova, Mashhoor Al-wardat, Gregory Beskin, Tatyana in black holes, pulsars, white dwarfs and flashing stars. Borkova, Alexander Burenkov, Victor Bychkov, Eugene The Laboratory of Large Scale Structure is mainly con- Chentsov, Sergei Ermakov, Timur Fatkhullin, Gazinur Gala- centrated on the CCD photometry of nearby dwarf galaxies. zutdinov, Olga Galazutdinova, Yuri Glagolevskij, Sergey From the study of their distances, kinematics and structure, Karpov, Valentina Klochkova, Alexei Kniazev, Victoria Ko- the main characteristics of the Local Group of galaxies are marova, Alexander Kopylov, Flera Kopylova, Vladimir Ko- derived. rchagin, Dimitry Makarov, Lidia Makarova, Vladimir Mar- The Laboratory of High Angular Resolution Methods per- sakov, Yuri Mishurov, Sofia Mitronova, Faig Musaev, Igor forms the speckle interferometric study of binary and mul- Naselsky, Natalia Orlova, Vladimir Panchuk, Alexander tiple stars with the diffraction-limited resolution of the 6-m Panferov, Inna Panferova, Vladimir Plokhotnichenko, Eu- telescope in the visible and in the infrared spectral region. gene Pluzhnik, Alexander Pramsky, Simon Pustilnik, Iosif Stellar fundamental parameters are derived for different Romanyuk, Abid Rzayev, Alla Shapovalova, Margarita Sha- types of stars from computed speckle interferometric orbits rina, Yuri Shchekinov, Zalikha Shkhagosheva, Olga and magnitude differences. The main attention is given to Sholukhova, Vladimir Sokolov, Nikolai Tikhonov, Andrei stars at the lower end of the main sequence. Ugryumov, Gennady Valyavin, Eduard Vorobyov and Mak- Recently V. Klochkova et al. presented spectroscopic ob- sim Yushkin. The Resident Director of the INI Branch is servations of the peculiar variable V838 Mon during the pe- Zalikha Shkhagosheva. riod from the second light outburst until the fast dimming. The Special Astrophysical Observatory ͑SAO͒ was estab- They described high resolution (RϷ60000) high S/N spectra lished in June 1966 as a research institute of the Department obtained a day before the second light maximum and low of General Physics and Astronomy of the USSR Academy of resolution (RϷ6000) spectra covering the whole period. The Science. The principal instruments of the Observatory are the temporal run of intensities and radial velocities of various optical telescope BTA ͑Big Telescope Azimuthal͒ with the 6 lines is presented. Using NaIDISlines They determined the meter main mirror and the radio telescope RATAN-600 ͑Ra- reddening distance of V838 Mon d Ͼ 3.1 kpc, and kinematic dio Telescope of the Academy of Science͒ with the ring distance d Ͼ 4 kpc. They estimated that V838 Mon is multi-element antenna 600 meter in diameter. The observa- slightly metal deficient but otherwise has a quite solar-like tory performs telescope observations under programs ap- chemical composition except for enhanced abundances of Li, proved by the Allocation Committee and carries out its own Ba and La. ͑2004, A&A, 416, 1107͒ fundamental research in the field of astrophysics. D. Makarov et al. studied the phenomenon of the very ISAAC NEWTON INSTITUTE OF CHILE 23 local (Ͻ3 Mpc͒ Hubble flow on the basis of the data of interferometric measurements collected mainly at the 6 m recent precision observations. A set of computer simulations BTA telescope of the Special Astrophysical Observatory in was performed to trace the trajectories of the flow galaxies Zelenchuk. back in time to the epoch of the formation of the Local N. A. Tikhonov, O. A. Galazutdinova et al. published the Group. It was found that the initial conditions of the flow are results of stellar photometry of polar ring galaxies NGC drastically different from the linear velocity-distance rela- 2685 and NGC 4650A, using archival data obtained with the tion. The simulations enabled also to recognize the major Hubble Space Telescope’s Wide Field Planetary Camera 2 trends of the flow evolution and identify the dynamical role ͑2004, AJ, 127, 789͒. They also studied the Stellar Content of universal antigravity produced by cosmic vacuum ͑2004, of the Ring in NGC 660 ͑2004, A&A, 421, 833͒. A&A, 415, 19͒. V.F. Gopka, F.A. Musaev, and G.A. Galazutdinov present A. Kniazev, A. Pramsky, S. Pustilnik, and A. Ugryumov results of chemical abundances of the mild barium star HD continued to work on the detailed studies of extremely metal- 202109 (␨Cyg) determined from the analysis of a spectrum ͑ ϭ 1 ͑ ͒ deficient XMD, (Z 20 Zo) blue compact galaxies BCGs . obtained by using the 2-m telescope at the Peak Terskol In particular, the results of the deep multiband photometry of Observatory and a high-resolution spectrometer with R ϭ 1 the galaxy SBS 0335-052 E (Z 42 Zo) evidence for the ϭ80000, signal to noise ratio Ͼ100. They also present the ages of its oldest stars of less than 500 Myr ͑2004, A&A, atmospheric parameters of the star determined using various ͒ ϩ ϭ 1 425, 51 . For HS 0822 3542 (Z 30 Zo) situated deeply in methods including iron-line abundance analysis. For line a nearby void, they discovered and studied a dwarf compan- identifications, they use whole-range synthetic spectra com- ion, triggered it current ͑probably the first͒ star formation puted from Kurucz’s database and the latest lists of spectral episode ͑2003, A&A, 409, 917͒. For a luminous XMD BCG lines. Among the determined abundances of 51 elements, ϩ ϭ 1 those of P, S, K, Cu, Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, In, HS 0837 4717 (Z 20 Zo) they discovered very large ni- trogen excess, and argued that this phenomenon, like in a Sm, Gd, Tb, Dy, Er, Tm, Hf, Os, Ir, Pt, Tl, and Pb were not few other luminous BCGs, is related to their recent merger investigated previously. Assuming that the overabundance nature ͑2004, A&A, 419, 469͒. Besides, they prepared, based pattern of Ba stars is due to binary accretion, the observed on the SDSS DR1 database, a catalog of about 600 HII gal- abundance pattern of the neutron-capture process elements in axies with the measured by the classic T method oxygen HD 202109 can be explained by combining the AGB star e ͑ abundances ͑2004, AJ, 127, 704͒. nucleosynthesis and the wind accretion scenario 2004, ͒ E. Vorobyov in collaboration with U. Klein, Yu. Shcheki- A&A, 413, 1105 . nov, and J. Ott performed numerical hydrodynamical model- Additionally they found a mutual relations between col- ling of supernova-driven shell formation with a purpose to umn densities of H2 , CH and CO molecules as well as reproduce a giant HI ring ͑diameter 1.7 kpc͒ in the dwarf between the latter and strengths of the major 5780 and 5797 irregular galaxy Holmberg I͑Ho I͒͑2004, A&A, 413, 939͒. diffuse bands are presented and discussed. The CH radical V. Korchagin, T. Borkova et al. have re-estimated the seems to be a good H2 tracer, possibly better than CO.Itis surface density of the Galactic disk in the solar neighborhood also demonstrated that the molecular fraction of the H2 mol- within Ϯ 0.4 kpc of the Sun using parallaxes and proper ecule is correlated with an intensity ratio of 5797 and 5780 motions of a kinematically and spatially unbiased sample of DIBs, suggesting the possible formation of narrow DIB car- 1476 old bright red giant stars from the Hipparcos catalog riers in denser clouds, dominated by molecular hydrogen and with measured radial velocities from Barbier-Brossat & reasonably shielded from ionizing UV radiation by small Figon ͑2000͒. They determined the vertical distribution of dust grains ͑2004, A&A, 414, 949͒. the red giants as well as the vertical velocity dispersion of Kniazev, Y. Alexei, Pustilnik, A. Simon, Pramskij, and G. the sample, ͑14.4 Ϯ 0.3 kmsϪ1ec͒, and combined these to Alexander present results of a pilot study to use imaging data derive the surface density of gravitating matter in the Galac- from the Sloan Digital Sky Survey ͑SDSS͒ to search for low tic disk as a function of the Galactic coordinate z ͑2003, AJ, surface brightness ͑LSB͒ galaxies. For their pilot study They 126, 2896͒. use a test sample of 92 galaxies from the Impey et al. catalog E.A. Pluzhnik, Z.U. Shkhagosheva et al. presented the distributed over 93 SDSS fields of the Early Data Release new results of binary and multiple star speckle interferom- ͑EDR͒. Many galaxies from the test sample are either LSB or etry based upon observations made at the 6-m BTA telescope dwarf galaxies. To deal with the SDSS data most effectively, of the Special Astrophysical Observatory in Zelenchuk. a new photometry software was created, which is described Relative positions from the ground-based telescopes carried in this paper. They present the results of the selection algo- out over many years remain the only effective source of or- rithms applied to these 93 EDR fields. Two galaxies from the bital parameters. Together with the Hipparcos parallaxes and Impey et al. test sample are very likely artifacts, as con- differential magnitudes, the orbits allow the estimation of firmed by follow-up imaging. With their algorithms They mass-sums of the components, their luminosities and spectral were able to recover 87 of the 90 remaining test sample types. The mass ratio, period and eccentricity distributions galaxies, implying a detection rate of ϳ96.5%. The three can be studied for the systems from their sample ͑2004, missed galaxies fall too close to very bright stars or galaxies. A&A, 422, 627͒. In addition, 42 new galaxies with parameters similar to the E.A. Pluzhnik, Z.U. Shkhagosheva et al. prepared paper test sample objects were found in these EDR fields ͑i.e., ‘‘Orbits of new Hipparcos binaries. I’’ ͑2004, A&A in ϳ47% additional galaxies͒. They present the main photo- press͒. The orbits were determined from visual and speckle metric parameters of all identified galaxies and carry out first 24 ANNUAL REPORT statistical comparisons. They tested the quality of their pho- population are dwarf ͑dIr, dIm, and dSph͒ galaxies with MB tometry by comparing the magnitudes for their test sample Ͼ-17.0, which contribute about 4% to the local luminosity galaxies and other bright galaxies with values from the lit- density, and roughly 10%-15% to the local H I mass density. erature. All these tests yielded consistent results. They The H I mass-to-luminosity and the H I mass-to-total ͑in- briefly discuss a few unusual galaxies found in their pilot dicative͒ mass ratios increase systematically from giant gal- study, including an LSB galaxy with a two-component disk axies toward dwarfs, reaching maximum values about 5 in and 10 new giant LSB galaxies ͑2004, AJ, 127, 704͒. solar units for the most tiny objects. For the Local Volume More recently they released the first edition of the SDSS disklike galaxies, their H I masses and angular momentum H II galaxies with Oxygen abundances Catalog ͑SHOC͒, follow Zasov’s linear relation, expected for rotating gaseous which is a listing of strong emission-line galaxies ͑ELGs͒ disks being near the threshold of gravitational instability, fa- from the Sloan Digital Sky Survey ͑SDSS͒. Oxygen abun- vorable for active star formation. They found that the mean dances have been obtained with the classic Te method. They local luminosity density exceeds 1.7-2.0 times the global describe the method exploiting the SDSS database to con- density, in spite of the presence of the Tully void and the struct this sample. The selection procedures are described absence of rich clusters in the Local Volume. The mean local and discussed in detail, as well as some problems encoun- H I density is 1.4 times its ‘‘global’’ value derived from the tered in the process of deriving reliable emission line param- H I Parkes Sky Survey. However, the mean local baryon ⍀ Ͻ ϭ eters. The method was applied to the SDSS Data Release 1 density b ( 8Mpc) 2.3% consists of only a half of the ͑ ͒ ͑ ⍀ ϭ͑ Ϯ ͒ ͑ DR1 . They present 612 SDSS emission-line galaxies 624 global baryon density, b 4.7 0.6 % Spergel et al., separate SDSS targets in total͒, for which the oxygen abun- published in 2003͒. The mean-square pairwise difference of dances 12ϩlog(O/H) have rms uncertainties р0.20dex. radial velocities is about 100 km sϪ1 for spatial separations The subsample of 263 ELGs ͑272 separate SDSS targets͒ within 1 Mpc, increasing to ϳ300 km sϪ1 on a scale of ϳ3 have an uncertainty р0.10dex, while 459 ELGs ͑470 sepa- Mpc. They also calculated the integral area of the sky occu- rate SDSS targets͒ have an uncertainty р0.15dex. The cata- pied by the neighboring galaxies. Assuming the H I size of log includes the main parameters of all selected ELGs, the spiral and irregular galaxies to be 2.5 times their standard intensities and equivalent widths of hydrogen and oxygen optical diameter and ignoring any evolution effect, They ob- emission lines, as well as oxygen abundances with their un- tain the expected number of the line-of-sight intersections certainties. The information on the presence of Wolf-Rayet with the H I galaxy images to be dn/dzϳ0.4, which does not blue and/or red bumps in 109 galaxies is also included. With contradict the observed number of absorptions in QSO spec- the use of combined g, r, i SDSS images they performed tra ͑2004, AJ, 127, 2031͒. visual morphological classification of all SHOC galaxies. E.I. Vorobyov, Yu.A. Shchekinov, E.O. Vasiliev, report Four hundred sixty-one galaxies (ϳ75%) are classified as that the multiple SN explosions in disk galaxies efficiently confident or probable blue compact galaxies ͑BCG/BCG?͒, evacuate gas and form cavities with the sizes and shapes of 78 as irregular ones, 20 as low surface brightness galaxies the surrounding envelopes determined by the total amount of ͑LSBG͒, 10 as obviously interacting, and 43 as spiral galax- injected energy and by the initial gas distribution. Such cavi- ies. In creating the catalog, 30 narrow-line active galactic ties are seen as HI holes when observed in face-on galaxies. nuclei and 69 LINERs were also identified; these are also Gas hydrodynamics simulations are performed to obtain the presented apart of the main catalog. We outline briefly the quantitative characteristics of HI holes that could serve for content of the catalog, and the prospects of its use for statis- the determination of the gas vertical scale height and the tical studies of the star formation and chemical evolution corresponding dark matter content and its distribution. issues. Some of these studies will be presented in the forth- Among these characteristics is the ratio of the maximum col- coming paper. Finally, they show that the method presented umn density in the HI ring surrounding the hole to the back- by Kniazev et al. for calculating Oϩ/Hϩ using intensities of ground HI column density and the vertical expansion veloc- the ͓OII͔␭␭7320, 7330 lines for SDSS emission-line spec- ity of gas in the HI ring. They show that in some cases the tra in the absence of ͓OII͔␭3727 line appears to yield reli- extragalactic background ionizing radiation may produce HI able results over a wide range of studied oxygen abundances: holes in the outer regions of galaxies, and can account for the 7.10Ͻ12ϩlog(O/H)Ͻ8.5 ͑2004, AJss, 153, 429͒. existence of HI holes in nearby face-on galaxies with the D.I. Makarov, in a fruitful collaboration with Karachent- apparent lack of an underlying stellar population ͑2004, sev, D. Igor, Karachentseva, E. Valentina, Huchtmeier, and A&A, 416, 499͒. K. Walter present an all-sky catalog of 451 nearby galaxies, They propose ͑Y. Shchekinov and A. Sobolev͒ that the each having an individual distance estimate DՇ10Mpc or a interaction of stellar wind with the surface of a circumstellar Ͻ Ϫ1 ͑ ͒ radial velocity VLG 550 km s . The catalog contains accretion or protoplanetary disk can result in the accelera- data on basic optical and H I properties of the galaxies, in tion of relativistic electrons in an external layer of the disk, particular, their diameters, absolute magnitudes, morphologi- and produce synchrotron radiation. Conservative estimates ϳ 5 cal types, circumnuclear region types, optical and H I surface give a total synchrotron luminosity Ls 10 L᭪ for a cen- Ϫ6 Ϫ1 brightnesses, rotational velocities, and indicative mass-to- tral star with M˙ ϭ10 M ᭪yr , comparable with the value luminosity and H I mass-to-luminosity ratios, as well as a observed around the TW object in the W3͑OH͒ region ͑2004, so-called tidal index, which quantifies the galaxy environ- A&A, 418, 1045͒. ment. They expect the catalog completeness to be roughly They show ͑Yu. Shchekinov and E. Vasiliev͒ that the 70%-80% within 8 Mpc. About 85% of the Local Volume presence of ultra-high energy cosmic rays in the universe in ISAAC NEWTON INSTITUTE OF CHILE 25

the pre-ionization epoch enhances significantly H2 kinetics correlated with peaks of the gas distribution, but they do not in virialized halos. It results in more efficient radiative cool- necessarily coincide with them. Therefore, a large scatter in ing and decreases the lower mass limit of the first star- the dust-to-gas ratios is expected. The appearance of the dust forming systems. Consequently, the fraction of baryons con- is more cellular ͑i.e. sometimes connecting different spiral tained in the first luminous objects and their contribution to features͒, whereas the gas is organized in a multi-armed spi- the reionization of the universe can significantly increase in ral structure. comparison with the standard scenario ͑2004, A&A, 419, N. Orlova and Ch. Theis found that an admixture of 2% 19͒. dust ͑relative to the mass of the gas͒ destabilizes gaseous V.N. Komarova et al. report on deep UBVRI-imaging of disks substantially, whereas dust-to-gas ratios below 1% the field of the 17.3 Myr radiopulsar PSR B0950ϩ08 ob- have no influence on the evolution of the gaseous disk. For a tained with the ESO/VLT/FORS1. Firm detection of the can- high dust-to-gas ratio of 10% the instabilities reach a satura- didate pulsar optical counterpart in the BVRI bands with the tion level already after 30 Myr. The stability of the gaseous ϭ Ϯ ϭ Ϯ ϭ magnitudes B 27.06 0.35, V 27.05 0.15, Rc 26.49 disks also strongly depends on their Toomre parameter. But Ϯ ϭ Ϯ 0.10 and Ic 26.20 0.17 enabled us to study, for the even in hot gaseous disks a destabilizing influence of the first time, the broadband spectrum of the object. The derived dust component has been found ͑2004, A&A, 418, 959͒. ϳ 0.24 arcsec offset of the object from the radiopulsar po- G. Valyavin, O. Kochukhov, and N. Piskunov discuss the sition is insignificant within the 0.21 arcsec uncertainties of properties of atmospheres of chemically peculiar magnetic their astrometry and ϳ 0.75 arcsec seeing value during the stars. The slow evolution of global magnetic fields leads to observations. The positional coincidence and unusual colors the development of an induced electric current in all conduc- of the candidate ensure us that they likely detect the optical tive atmospheric layers. The Lorentz force, which results emission from PSR B0950ϩ08. The optical-near-UV spec- from the interaction between a magnetic field and the in- trum of the pulsar has a negative slope and can be fitted by a duced current, may change the atmospheric structure and ␯ power law F␯␣ with ␣ϭ0.65Ϯ0.40, suggesting nonthermal provide insight into the formation and evolution of stellar emission. Within errors, the optical flux is consistent with the magnetic fields. We developed a model atmosphere code that power law fit of the ROSAT spectrum from the X-ray coun- takes into account the Lorentz force in the equation of hy- terpart. They analyze their results together with the available drostatic equilibrium, and computed a number of model at- multiwavelength data on other isolated pulsars of different mospheres for magnetic A and B stars. The surface distribu- ages detected in the optical range and find a significant cor- tion of a magnetic field was assumed to be a dipole, slightly relation between their optical and 2-10 keV X-ray luminosi- distorted by the induced atmospheric electric current. The ties. This implies an origin of the nonthermal emission in interaction between the magnetic field and electric current is both spectral domains. These objects show a significantly modelled in detail, taking into account microscopic proper- non-monotonic evolution of the efficiency of the optical-X- ties of the stellar plasma. The presence of a significant Lor- ray photon production from the pulsar spindown power, with entz force leads to substantial modification of the atmo- a pronounced minimum at the beginning of the middle-age spheric structure and in particular the pressure stratification, epoch and comparably high efficiencies of younger and older which in turn influences the formation of absorption spectral pulsars. This suggests different sensitivities of the photon features, especially hydrogen Balmer lines. Furthermore, production processes to the Goldreich-Julian current in mag- they find that rotational modulation of the disk-average pa- netospheres of different age pulsars ͑2004, A&A, 417, rameters of a global stellar magnetic field causes character- 1017͒. istic rotational variability of hydrogen lines. With their Dynamically cold components are well known to destabi- model, observable effects correspond to induced electric cur- lize hotter, even much more massive components. E.g. stellar rents of the order of 10-11 cgs, which requires characteristic disks can become unstable by a small admixture of cold gas field evolution times 2-3 orders of magnitude shorter than the or proto-planetary disks might be destabilized by a small field decay time estimated for magnetic A and B stars assum- fraction of dust. In this paper, they studied the dynamical ing fossil dipolar field topology in the stellar interior. Using influence of a cold dust component on the gaseous phase in the computations of their model atmospheres They consider the central regions of galactic disks. They performed two- an observational aspect of the problem and attempt to inter- dimensional hydrodynamical simulations for flat multi- pret photometric data on the variability of hydrogen lines component disks embedded in a combined static stellar and within the framework of simplest model of the evolution of dark matter potential. The pressure-free dust component is global magnetic fields. With the hydrogen line data they find coupled to the gas by a drag force depending on their veloc- tentative support for the presence of a non-negligible Lorentz ity difference. force in the atmospheres of some magnetic chemically pecu- It turned out that the most unstable regions are those with liar stars ͑2004, A&A, 420, 993͒. either a low or near to minimum Toomre parameter or with A.I. Kopylov, V.S. Artyukh, and F.G. Kopylova present rigid rotation, i.e. the central area. In that regions the dust- the results of optical identification of 248 interplanetary scin- free disks become most unstable for high azimuthal modes tillating ͑IPS͒ radio sources from the Pushchino Survey ͑PS͒ ͑m ϳ 8͒, whereas in dusty disks all modes have a similar in the area of 0.11 sr with the center at ␣ ϭ 10h28m, ␦ ϭ amplitude resulting in a patchy appearance. The structures in ϩ41o. All 260 counterparts of IPS radio sources from the 7C the dust have a larger contrast between arm and inter-arm and FIRST catalogs, which had been found in Paper I, were regions than those of the gas. The dust peaks are frequently considered. They used USNO-B1.0 catalog ͑limiting magni- 26 ANNUAL REPORT tude mRϷ 21͒ for the optical identification and searched the 14. THE INI TAJIKISTAN BRANCH literature to find optical data for fainter objects. Photometric The Isaac Newton Institute opened its Tajikistan Branch and spectroscopic observations were conducted on the 1-m in July 2000. The formal Agreement has been signed with and 6-m telescopes of SAO RAS. Optical magnitudes or Prof. Pulat Babadzhanov, Director of the Institute of Astro- deep limits for 22 objects and redshifts for 26 ones have been physics of the Academy of Sciences of Tajikistan. obtained. In total, they collected optical data for 116 ͑68 with The staff of the INI Tajikistan Branch are: Obid Alimov, redshift͒ counterparts of the PS radio sources. For the sub- Pulat Babadzhanov, Khursand Ibadinov, Subhon Ibadov, sample of the PS quasars ͑41 objects͒ the redshift distribu- Gulchehra Kokhirova, Natalia Konovalova, Nasridin Mini- tion was compared to those of several other samples of qua- kulov, Firouz Sakhibov and Fanisa Tupiyeva. The Resident sars ͑BRL, 3CRR, MQS, B3-VLA, 7CRS I-III and PKS 0.25 Director of the INI Branch is Pulat Babadzhanov. Jy͒ which have complete or nearly complete redshift infor- The modern astronomy in Tajikistan began in 1932 after mation ͑2004, A&A, 421, 455͒. the end of the work of Tajik-Pamir complex expedition Between 1996 and 2002 A.I. Shapovalova, V.T. Dorosh- ͑1928-1932͒ which appreciated rather favorable astroclimatic enko, A.N. Burenkov et al. carried out a spectral monitoring conditions and advantageous geographical location of Tajiki- program for the Seyfert galaxy NGC 5548 with the 6-m and stan. In 1932 a Tajik Astronomical Observatory ͑TAO͒ was 1-m telescopes of SAO ͑Russia͒ and with the 2.1-m tele- organized in the outskirts of Dushanbe. The principal direc- scope of Guillermo Haro Observatory ͑GHO͒ at Cananea, tions of scientific research for the Observatory, namely, me- Mexico. High quality spectra with S/N Ͼ 50 in the con- teors, comets, and variable stars, were chosen taking into tinuum near H␣ and H␤ were obtained, covering the spectral account the geographical location and climatic conditions of range ϳ͑4000-7500͒ A with a ͑4.5 to 15͒- resolution. They Tajikistan. These direction, alongside with others, remain as found that both the flux in the lines and the continuum gradu- the main to this day. ally decreased, reaching minimum values during May-June In 1958 on the base of the observatory, the Institute of 2002. In the minimum state, the wings of H␤ and H␣ be- Astrophysics of the Tajik Academy of Sciences was created. came extremely weak, corresponding to a Sy1.8 type, not to It consisted of three departments: Department of meteor as- a Sy1, as observed previously when the nucleus was brighter. tronomy, Deparment of comets, Department of variable The line profiles were decomposed into variable and constant stars. Afterwards the Department of theoretical astrophysics components. The variable broad component is well corre- ͑1962͒, Laboratory of experimental astrophysics ͑1972͒, and lated with the continuum variation. It consists of a double Department of astrometry ͑1975͒ were created. Ϫ peaked structure with radial velocities ϳ 1000 km s 1 rela- For subsequent 30 years after the creation of the Institute, tive to the narrow component. A constant component, whose the following three its modern observational bases were presence is independent of the continuum flux variations, build: shows only narrow emission lines.The mean, rms, and the averaged over years, observed and difference line profiles of • In 1963-1971 the Gissar astronomical observatory ͑Gis- ͒ H␤ and H␣ reveal the same double peaked structure. The sAO was build at a distance 14 km south-west from relative intensity of these peaks changes with time. During Dushanbe. It domes houses: a 70-cm reflector supplied with electron-optical, electrophotometric and polarimet- 1996, the red peak was the brightest, while in 1998-2002, the ric receiving apparatus, intended for observations of blue peak became the brighter one. Their radial velocities variable stars and comets and a 40-cm Zeiss astrograph ϳ͑ ͒ Ϫ1 vary in the 500-1200 km s range. In 2000-2002, a for observations of asteroids, comets and variable stars. ␣ ␤ distinct third peak appeared in the red wing of H and H The observatory is also equipped with a high-precision line profiles. The radial velocity of this feature decreased astronomical camera ͑Dϭ1m,Fϭ0.75 m͒ for photo- between 2000 and 2002: from the observed profiles, from ϳ graphic observation of artificial Earth satellites, comets, ϩ͑2500-2600͒ km sϪ1 to ϳ ϩ2000 km sϪ1 and is clearly meteors. One of lagest photographic meteor patrol is seen on the difference profiles. The fluxes of the various established in Gissar observatory. It consists of 16 parts of the line profiles are well correlated with each other wide-field cameras MK-75 ͑Fϭ75 cm, D/F-1:3.5͒ and ͑ ϭ ϭ ͒ and also with the continuum flux. The blue and red parts of 24 small cameras MK-25 F 25 cm, D/F 1:2.5 . Ob- the line profiles at the same radial velocities vary in an al- servations of meteors are carried out also using fireball cameras equipped with ‘‘fish-eye’’ lenses. most identical manner. Shape changes of the different parts of the broad line are not correlated with continuum variations • Sanglokh observatory, the construction of which was and, apparently, are not related to reverberation effects. completed in 1980, is located in a south-east of Dush- anbe at a distance of about 90 km. It was build at the Changes of the integral Balmer decrement are, on average, top of Sanglokh Mountain, the astroclimatic conditions anticorrelated with the continuum flux variations. This is of which have been widely recognized with a Ritchey- probably due to an increasing role of collisional excitation as Chretien 1-m telescope. the ionizing flux decreases. The behavior of the Balmer dec- • Pamir high-mountain observatory, the so-called Solar rement of the various parts of the line profiles was different ground-based astronomical complex ‘‘Pamir’’ ͑situated in 1996-2000 as compared with the 2001 behavior. Our re- at an altitude of 4350 m above sea levet and enjoing sults favor the formation of the broad Balmer lines in a tur- 250 clear nights per year͒. It is located in the Murgab bulent accretion disc with large and moving ‘‘optically district ͑East Pamir͒ of the Gorno-Badakhshan Autono- thick’’ inhomogeneities, capable of reprocessing the central mous Region of Tajikistan. There a 70-cm telescope RT source continuum ͑2004, A&A, 422, 925͒. 700 ͑Cassegrain optical system͒ and solar telescope are ISAAC NEWTON INSTITUTE OF CHILE 27

installed. Pamir observatory, with its unique astrocli- graphed path and last until the end of the visible trajectory. mate, is an excellent long-term site for astronomical Different possible meteoroid ablation mechanisms causing submillimeter, IR and optical observations. the flickering of the bright Geminids were discussed. The Nature of meteoroids and phenomena accompanying obtained results permit them to conclude that the observed flight of these bodies in the Earth atmosphere, atmospheric high-frequency flickering of Geminid fireballs may be ex- trajectories, meteor radiation and ionization, heliocentric or- plained by a autofluctuating mechanism of the meteoroid ab- bit of meteoroids, distribution of meteor matter in the near- lation, i.e. by melting and cyclic detachment of the surface Earth space and, at last, origin and evolution of meteoroid layer of meteoroid matter with a period corresponding to the streams and meteor showers—all of these problems are the observed period of the flickering. area of scientific interest of scientist of the Institute of astro- P.B. Babadzhanov investigated the orbital evolution of physics of the Tajik Academy of sciences. the near-Earth asteroid 2000 PG3 with a comet-like albedo, Physics of comets is the other important direction of sci- moving on comet-like orbit, under gravitational action of six entific research at the Institute of Astrophysics, Tajik Acad- planets ͑Mercury-Saturn͒ and determined the theoretical geo- emy of Sciences. These researchers cover all sections of centric coordinates and velocities of four possible meteor cometary physics and an extensive observational and experi- showers associated with this objects. Using available pub- mental material on comets is obtained there. lished data the theoretically predicted showers were identi- Observations of variable stars in Tajikistan have begun fied with the observed ones. The character of the orbit and from the earliest days of the formation of the Astronomical low albedo of 2000 PG3, and the existence of observed me- Observatory in Dushanbe. A unique photo-archives, a ‘‘Sky teor showers associated with 2000 PG3 provide evidence Survey,’’ consisting of almost 70,000 sky negatives is pre- supporting the conjecture that this object may be of a com- served. Based on this archive several novaes and more than etary origin. 100 variables were discovered in T-associations, than Fea- Pulat Babadzhanov and Gulchehra Kokhirova determined tures of light curves, variability of period of variables of the radiant, velocity and orbital elements of the July Alfa- different types, and the oscillations in brightness of novae Capricornid fireball TN920729 of minus ninth absolute mag- ͑ ͒ have been studied. nitude which flew above Dushanbe Tajikistan on the night Theoretical investigations of the dynamical phenomenon of July 29/30, 1992 and was photographed from two obser- ͑ ͒ of the collective gravitational interactions of stars in galaxies vatories Gissar and Sanglokh of the Institute of Astrophys- have been widely developed at the Institute. Investigation of ics, Tajik Academy of Sciences. Mass and density of the star formation in galaxies have shown, that spiral waves of fireball’s progenitor were inferred from photometric mea- surements of the films and find to be equal to 1.023 kg and density in galaxies counted not only in the features of motion 3 of stars and interstellar gas, but also in peculiarity of late 2 g/cm . star-formation processes. In 2004 members of the INI Tajikistan Branch continued 15. THE INI UZBEKISTAN BRANCH investigating the physics and dynamics of Near-Earth Ob- The Isaac Newton opened its Uzbekistan Branch in Au- jects ͑NEOs͒, namely, asteroids, comets, meteoroid streams gust 2000. The formal Agreement has been signed with Prof. and meteoroids. Shukhrat Ehgamberdiev, Director of the Ulugh Beg Astro- Pulat Babadzhanov and Gulchehra Kokhirova ͑A&A, nomical Institute of the Uzbekistan Academy of Sciences. 424, 317, 2004͒ carried out a quantitative analysis of prism At present the staff of the Isaac Newton Institute in spectra of eight meteors belonging to Perseid and Orionid Uzbekistan are: Bobomurat Ahmedov, Abdikul Ashurov, meteor showers and to sporadic background. For this pur- Venera Batirshinova, Otabek Burkhonov, Shukhrat Ehgam- pose a method used, that is applicable in spectrometric study berdiev, Manzura Eshankulova, Olga Ezhkova, Evelina of the solar prominences and is based on the assumption of Gaynulina, Konstantin Grankin, Alisher Hojaev, Mansur local thermodynamic equilibrium in the radiaing volume. Ibrahimov, Sabit Ilyasov, Shukur Kholikov, Oleg Ladenkov, According to this method, the monochromatic light curves Stanislav Melnikov, Karomat Mirtadjieva, Muydinjon for the H and K lines of the ionized calcium doublet are Muminov, Salakhutdin Nuritdinov, Israil Sattarov, Ale- constructed and from ratio of their intensities at selected ksander Serebryanskiy, Fazliddin Shamshiev, Chori Sher- points along the meteor trajectories the column and volum danov, Yusuf Tillaev and Mamnun Zakirov. The Resident concentrations of calcium ions determined equal accordingly Director of the INI Branch is Salakhutdin Nuritdinov. Ϫ Ϫ to 1016Ϫ1018 cm 2 and 1013Ϫ1015 cm 3. The volume con- Ulugh Beg Astronomical Institute of the Uzbekistan Ϫ centration of free electrons is defined equal to 4x1013cm 3, Academy of Sciences ͑UBAI͒ is one of the oldest astronomi- and the exitation temperature is calculated along the meteor cal institutions of the former Soviet Union. It was founded in path. 1873. The Central Asian area where Uzbekistan lies has ab- Pulat Babadzhanov and Natalia Konovalova ͑A&A, 2004, solute maximum of clear sky time for the whole Euro-asian in the press͒ investigated the same features of Geminid me- continent. This makes the area particularly important for op- teoroids disintegration in the Earth’s atmosphere. Among 11 tical astronomical observations. As a result of the site testing bright Geminid meteors photographed at the Institute of as- expeditions organized by UBAI and Sternberg Astronomical trophysics, Tajik Academy of Sciences, 3 displaced distinct Institute ͑Moscow͒ at the early 70s Maidanak mountain high-frequency ͑more than 100 Hz͒ pulsations of brightness, ͑2700m͒ located 120 km south of the famous historical city or flickering, which begin at the middle of their photo- of Samarkand was selected for an observatory. In August 28 ANNUAL REPORT

1996 a seeing monitoring at Mt. Maidanak was started with yasov, and a number of young scientists. The group Differential Image Motion Monitor of ESO, designed by M. carries out the CCD observations of some quasars and Sarazin and used for Paranal and La Silla sites testing. After active galactic nuclei. one year the results of the seeing measurements showed a Several members of the Branch deliver lectures in the very high quality seeing conditions at Mt. Astronomy Department of the National University of Maidanak. Uzbekistan. The University was founded in 1918. The As- Starting in 2003 all scientific projects in Uzbekistan have tronomy Department of the University trains Bachelors, been converted to the competitive grant system. The current Masters, Post-graduates and Post-doctoral students. The sci- seven main research topics have been selected by the Center entific activity of the Department members are in the fields of Science and Technology of the Republic of Uzbekistan for of: Formation and evolution of Elliptical galaxies, Physics of the budget funding. They are related to the theoretical and Globular Clusters, Dynamics of Galaxy clusters, Physics of observational research in galaxies, photometric observation lensed Quasars, and Close binary systems. In particular, the of eclipsing binaries, observational studies of young stars, scientific group of Prof. S.P. Nuritdinov researches early for- the study of solar activities etc: mation stages of galaxies and prof. M. Zakirov studies the influence of the third star on close binary system. • Gravitational lenses and collapsing galaxies. Investi- In 2004 the staff members of the INI Uzbekistan gators: Salakhutdin Nuritdinov, Karomat Mirtadjieva, Branch published about 20 papers in the refered journals Evelina Gaynulina, Otabek Burkhonov and a number of ͑Month.Not.RAS, Astron.J., Astronomy Reports of Russian postgraduate students. This group studies early evolu- Acad.Sci., and others͒. Most of all new members of the tion stages of spiral and other disk galaxies and gravi- Branch have worked more actively. For example, B. Ahme- tationally lensed quasars. Observations of gravitation- ally lensed quasars are carried out with 1.5-m telescope dov investigated electromagnetic fields outside an oscillating at the Maidanak Observatory using modern CCD- relativistic star, in particular the impact that oscillations have camera. The observations are carried out in collabora- on the electric and magnetic fields external to a relativistic tion with colleagues of Germany, Russia and Ukraine. star. Modelling the star as a relativistic polytrope with infi- In 2003, the Nuritdinov group received German grant nite conductivity in vacuum, he considered the solution of DFG ͑436 UZB113/5/0-1͒ for joint observations of the the general relativistic Maxwell equations both in the vicin- Gravitational Lens Systems. ity of the stellar surface and far from it, once a perturbative • The study of solar activities. Investigators: Shukhat velocity field is specified. He presented general analytic ex- Ehgamberdiev, Israil Sattarov, Shukur Kholikov, Ale- pressions that are not specialized to any particular magnetic ksander Serebryanskiy, Oleg Ladenkov, Chori Sher- field topology or velocity field. As a validating example, danov, and Yusuf Tillaev. This group carries out obser- however, he considered a dipolar magnetic field and the ve- vations in helioseismology in the frame of a number of locity field corresponding to the rotation of the misaligned International research programs and studies mecha- dipole. This application is also useful to calculate, for the nisms of the solar activity. Besides interiorstructure of first time, the general relativistic expression for the energy the Sun is also the aim of this group. loss through dipolar electromagnetic radiation and reveal that • Observational tests of the origin theory and early the widely adopted Newtonian expression underestimates stages of young stars. Investigators: Konstantin this loss by a factor of 2–6 depending on the stellar com- Grankin, Olga Ezhkova, Stanislav Melnikov, Manzura pactness. This correction could have important consequences Eshankulova, and a number of postgraduate students. in the study of the spin evolution of pulsars. The main aim of this group is observation of young A.E. Ashurov ͑AJ, 2004͒ studied the number of stellar stars in our Galaxy. The group created the most multi- color database. encounters in a globular cluster, per unit time with given changes in energy and direction of relative to the cluster • Development of complex program of near open clus- center, has been determined assuming an anisotropic field ters. Investigators: Muydinjon Muminov and a number of young scientists. The group has first epoch of near 50 star distribution function. An exact expression for the inte- open star clusters photographed 20-25 years ago. Today grated probability of such encounters is derived for the case they are photographing the second epoch as well as of equal mass stars, and ranges of physical variables are planning photometric observations. analyzed. The distributions of the probability and number of • Young stars and structure formation around them. encounters in a globular cluster with and without a black Investigators: Alisher Hojaev and a number of post- hole in the Plummer and King models are also studied. It is graduate students. They observe and research young shown that the influence of the black hole to the probability Ϸ stars in open star clusters and associations. distribution almost vanishes at the distance r0 1.55rc , • Dynamics of gravitating systems and electromag- where rc is the core radius of the cluster. Moreover, in the Ϫ netic fields around compact objects. Investigators: area of the radius (2 3)r0 strong encounters are significant Abdikul Ashurov, Bobomurat Ahmedov and a number and Fokker-Planck approximation cannot be used for model- of students. The group is studying encounters in galax- ing the dynamical evolution of globular clusters. The method ies with black hole and electromagnetic fields and is developed for determining the probability of distant waves around magnetized neutron stars. ͑weak͒, as well as close, encounters and for studying the • Nature of cores of galaxies and quasars. Investiga- dynamical evolution of the globular clusters in the space of tors: Mansur Ibrahimov, Venera Batirshinova, Sabit Il- the energy integral ͑E͒ and angular momentum per unit mass ISAAC NEWTON INSTITUTE OF CHILE 29

͑J͒ under close encounters. The paper is organized as fol- struments procured by Nedeljkovic from the Great War repa- lows. In Sect. 2, the exact expression for the integrated prob- rations, constitute still practically the only observing basis of ability of encounters is obtained. Ranges of physical vari- the Observatory. Currently mounted in appropriate pavilions ables are analyzed in Sect. 3. In Sect. 4, numerical results of are the following instruments: 1. Large Refractor - ZEISS the determination of the encounter probability in a globular 650/10550mm equatorial; 2. Solar spectrograph ͑monochro- cluster with and without a BH are presented. In order to matic͒ LITTROW, 9000 mm/100.000 developed by adapting compare the density probabilities, the Plummer and King to the ZEISS 200/3020 mm equatorial two astrocameras models are considered. Moreover, to estimate the magnitude TESSAR and PETZVAL 160/800 mm; 3. Large Transit In- of the effect of an anisotropic field star distribution on the strument ASKANIA 190/2578 mm; 4. Large Vertical Circle probability of encounters, the Plummer model is considered ASKANIA 190/2578 mm; 5. Astrograph ZEISS 160/800 in anisotropic and isotropic cases. A brief discussion and mm; 6. Photovisual Refractor ZEISS 135/1000 mm and 125/ conclusions are presented in Sect. 5. 1000 mm; 7. Transit Instrument BAMBERG 100/1000 mm and 8. Zenith-telescope ASKANIA 110/1287 mm.

16. THE INI YUGOSLAVIA BRANCH • 1. Influence of collisional processes on astrophysical The Isaac Newton Institute opened its Branch in Yugosla- plasma lineshapes: ͑principal invesigator Milan S. via in April 2002. The formal agreement has been signed Dimitrijevic͒ with Prof. Milan S. Dimitrijevic Director of the Belgrade • 2. Solar Spectral irradiance variability: ͑Istvan Astronomical Observatory. Vince͒ The staff of the Isaac Newton Institute in Belgrade are: • 3. Inverse problems in astrophysics: Doppler tomog- Edi Bon, Srdjan Z. Bukvic, Zorica Cvetkovic, Miodrag raphy: ͑Slobodan Jankov͒ Dacic, Milan S. Dimitrijevic, Stevan I. Djenize, Gojko R. • 4. Stellar physics: ͑Gojko Djurasevic͒ Djurasevic, Sanja R. Erkapic, Ljubinko M. Ignjatovic, Pre- • 5. Astrophysical spectroscopy of extragalactic ob- drag Jovanovic, Aleksandar Dj. Kubicela, Anatolij A. Mi- jects: ͑Luka Ch. Popovic͒ hajlov, Vladimir Milosavljevic, Nenad Milovanovic, Slo- 6. Position and motion of minor bodies of the Solar bodan Ninkovic, Dragomir Olevic, Luka Ch. Popovic, Srdjan • system: ͑Zoran Knezevic͒ S. Samurovic, Zoran Simic, Aleksandar Sreckovic, Natasa • 7. Investigations of double and multiple stars: M. Stanic, Dragana Tankosic and Dejan Urosevic. The staff ͑ ͒ of the INI Branch in Yugoslavia includes representatives of Georgije Popovic Belgrade Astronomical Observatory, Faculty of Physics of • 8. Structure, kinematics and dynamics of the Milky ͑ ͒ the Belgrade University and Institute of Physics. The Resi- Way: Milan Cirkovic dent Director of the Branch is Milan S. Dimitrijevic. • 9. History of astronomy among Serbs: ͑Slobodan ͒ The principal astronomical institution in Serbia is the Bel- Ninkovic grade Astronomical Observatory, one of the oldest scientific Serbian Astronomical Journal publishing by the Belgrade organizations and the unique autonomous astronomical insti- Astronomical Observatory and Department of Astronomy of tute in Yugoslavia. Its past development forms an important the Faculty of Mathematics of the Belgrade University is part of the history of science and culture in these regions. available on the WWW through the Astrophysical Data Sys- The decree of its founding conjointly with the Meteorologi- tem ͑ADS͒, thanks to the courtesy of the System’s holders. cal Observatory was signed on 20 March ͑7 April͒ 1887 by The WWW address is: http://adswww.harvard.edu.BOBeo. the Minister of Education and Church Affaires of Kingdom During 1999, the web site of the Belgrade astronomical ob- of Serbia Milan Kujundzic on the initiative of Milan Nedel- servatory has been made and the corresponding WWW ad- jkovic ͑Belgrade 27. Sept. 1857 - Belgarde 27 Dec. 1950͒,a dress is: http: //www.aob.bg.ac.yu. Moreover, the database professor of the Grand School ͑Belgarde University͒. Nedel- BELDATA has started to develop and it is available through jkovic was appointed first director of the newly founded Ob- the Internet with the address: http://www.aob.bg.ac.yu/ servatory. He governed Observatory until 1924, with a small BELDATA. The INI Yugoslavia Branch also has the Internet break when 1899-1900 Director was Djordje Stanojevic ͑Ne- address: http://www.aob.bg.ac.yu gotin, 7 April 1858 - Paris 24 Dec. 1921͒, the first Serbian In the course of its history, the Belgrade Astronomical astrophysicist, later on the rector of Belgrade University. Dj. Observatory grew to an institution of great importance in the Stanojevic was a great popularizer of astronomy and science history of science and culture of the Serbian people, not only in general; he was the driving force in the introduction of in the field of astronomy but also in meteorology, seismol- electrical light in Belgrade and other cities in Serbia, the ogy and geomagnetics. Linked to this institution are the builder of the first hydro-electric power station in Serbia, a names of the famous personalities in the history of science pioneer of industry of refrigerating appliances, the initiator who contributed to the Observatory, and the scientific of setting up a committee for cooling problems and of form- achievements of Serbian astronomers in general, having ing an international organization for cooling technique in earned esteem in the international scientific community as Paris in 1903. He was also the pioneer of the color photoga- well as to the young having a good perspective, in our coun- phy in Serbia. try too, in engaging in this beautiful and challenging science, Apart from its importance for astronomy and meteorol- in an ambience enabling them to achieve results of the high- ogy, the Belgrade Astronomical Observatory was a cradle of est value. the seismic and geomagnetic researches in Serbia. The in- In 2003 Luka Ch. Popovic, Edi Bon, Natasa Stanic and 30 ANNUAL REPORT

Aleksandar Kubicela investigated with E.G. Mediavilla the gravitational microlens distributions. On the other hand, the Ly␣ ;H␤ ;H␣ ; and Mg II ␭ϭ2798 line profiles of the Sey- optical depth for gravitational microlensing caused by cos- fert 1 galaxy III Zw 2. The shapes of these broad emission mologically distributed deflectors could be significant and lines show evidence of a multicomponent origin and also could reach 10Ϫ2 - 0.1 at z Ͼ 2. This means that cosmologi- show features that may be identified as the peaks due to a cally distributed deflectors may contribute significantly to the rotating disk. They proposed a two-component broad-line re- X-ray variability of high-redshifted QSOs ͑zϾ2͒. Consider- gion ͑BLR͒ model consisting of an inner Keplerian relativ- ing that the upper limit of the optical depth corresponds to istic disk and an outer structure surrounding the disk. The the case where dark matter forms cosmologically distributed results of the fitting of the four broad emission lines ͑BELs͒ deflectors, observations of the X-ray variations of unlensed considered here are highly consistent in both the inner and QSOs can be used for the estimation of the dark matter frac- outer component parameters. Adopting a mass of ϳ2 ϫ tion of microlenses. ϩ8 10 M᭪ for the central object, they found that the outer Investigation of Stark broadening parameters of Cd III radius of the disk is approximately equal for the four consid- spectral lines is of interest for a number of problems as for ered lines (ϳ0.01 pc͒. However, the inner radius of the disk example the laboratory plasmas, fusion plasmas and laser is not the same: 0.0018 pc for Ly␣ ; 0.0027 pc for Mg II, and produced plasmas research as well as for testing and devel- 0.0038 pc for the Balmer lines. This, as well as the relatively oping of the Stark broadening theory for multicharged ion broad component present in the blue wings of the narrow ͓O lines. Moreover, such data are of interest as well for the III͔ lines, indicates stratification in the emission-line region. consideration of stellar plasma, since with the development Using long-term H␤ ; observations ͑1972-1990, 1998͒ they of space born spectroscopic techniques, even trace elements found a flux variation of the BELs with respect to the ͓O III͔ become more and more of interest. The electron-impact lines. broadening mechanism is the main pressure broadening In 2004 Luka Ch. Popovic, Edi Bon and coworkers inves- mechanism in hot star atmospheres ͑having effective tem- տ ͒ tigated the structure of the emission line region in a sample perature Teff 10,000K , and it is of interest especially for A of 12 single-peaked Active Galactic Nuclei ͑AGNs͒. Using type stars and white dwarfs. Cd III Stark broadening data are the high resolution H␤ ; and H␣ ; line profiles observed with also of importance for the investigations of regularities and the Isaac Newton Telescope ͑La Palma͒ they study the sub- systematic trends particularly along isoelectronic sequences. structure in the lines ͑such as shoulders or bumps͒ which can The sophisticated strong coupling quantum mechanical indicate a disk or disk-like emission in Broad Line Regions ͑see e.g. Griem, 1974͒ or semiclassical-perturbation ͑Sahal- ͑BLRs͒. Applying Gaussian analysis they found that both Bre´chot, 1969͒ formalism for Stark broadening parameter kinds of emission regions, BLR and NLR, are complex. In calculations are not applicable in an adequate way, for a this sample the narrow ͓O III͔ lines are composites of two large number of interesting spectral lines of various emitters. components; NLR1 which have random velocities from 200 In such a case one can apply the modified semiempirical to 500 kmsϪ1 and systematic velocities toward the blue from method of Dimitrijevic´ and Konjevic´, which needs a consid- 20 to 350 kmsϪ1, and NLR2 with smaller random velocities erably smaller number of atomic data. The spectrum of Cd ͑100-200 kmsϪ1) and a redshift corresponding to the cosmo- III is poorly known, so that the case of the modified semi- logical one. The BLR also have complex structure and the empirical approach is justified. apply a two-component model assuming that the line wings Using a modified semiempirical approach, Nenad Milo- originate in a very broad line region ͑VBLR͒ and line core in vanovic, Milan S. Dimitrijevic, Luka Ch. Popovic and Zoran an intermediate line region ͑ILR͒. The VBLR is assumed to Simic have calculated in 2004, Stark line widths for 10 Cd be an accretion disk and the ILR a spherical emission region. III transitions for an electron density of 1017cmϪ3 and tem- The model fits very well the H␣ ; and H␤ ; line profiles of the peratures 10,000K, 20,000K, 50,000K, 100,000K, 150,000K AGNs. and 300,000K. Luka Ch. Popovic and Predrag Jovanovic studied in 2004 Atomic data, such as Stark widths ͑W͒ and shifts ͑d͒ are with A. F. Zakharov the contribution of microlensing to the useful for plasma diagnostic purposes in a wide range of X-ray variability of high-redshifted QSOs. Such an effect electron temperatures (T) for astrophysical and laboratory could be caused by stellar mass objects ͑SMO͒ located in a plasmas. In the last five years fluorine spectral lines have bulge or/and in a halo of this quasar as well as at cosmologi- become important for abundance investigations in various cal distances between an observer and a quasar. In the paper astrophysical plasmas. However, only four experiments per- they did not consider microlensing caused by deflectors in formed by Platisˇa et al. 1977, Puric´ et al. 1988, Djenizˇe our Galaxy since it is well-known from recent MACHO, et al. 1991 and Blagojevic´ et al. 1999, deal with investiga- EROS and OGLE observations that the corresponding opti- tions of Stark broadening parameters (W, d) of singly ionized cal depth for the Galactic halo and the Galactic bulge is fluorine spectral lines. A number of calculations of the Stark lower than 10Ϫ6. Cosmologically distributed gravitational parameters, related to the F II, F III spectral lines, on the microlenses could be localized in galaxies ͑or even in bulge basis of different theoretical approaches is presented in the or halo of gravitational macrolenses͒ or could be distributed literature. in a uniform way. They have analyzed both cases of such Stark widths ͑W͒ and shifts ͑d͒ of 5 singly ionized fluorine distributions. As a result of our analysis, they obtained that ͑FII͒ spectral lines within the 3sϪ3p,3sЈϪ3pЈ and 3d the optical depth for microlensing caused by stellar mass Ϫ4 f transitions and 5 doubly ionized fluorine ͑F III͒ spectral objects is usually small for quasar bulge and quasar halo lines within the 3sϪ3p transition have been measured in ISAAC NEWTON INSTITUTE OF CHILE 31

2004 by Aleksandar Sreckovic, Srdjan Bukvic, Stevan transfer through subphotospheric layers, for modelling of Djenize and Milan S. Dimitrijevic in a linear, low-pressure, some hot star atmospheres such as PG 1159 pre-white dwarfs pulsed arc discharge created in SF6 plasma at 30,400 with an effective temperature between 100,000 and Ϫ33,600K electron temperatures and at (2.75Ϫ2.80) 140,000K, as well as for fusion plasmas and laser-produced ϫ1023 mϪ3 electron densities. For Stark parameters of two F plasmas. The development of soft X-ray lasers, where Stark II and five F III lines there are no other experimental data. broadening data are needed to calculate gain values, to The widths and shifts have also been calculated using the model radiation trapping and to consider photoresonant semiclassical perturbation formalism ͑SCPF͒͑taking into ac- pumping schemes, provided an additional interest in such count the impurity of energy levels, i.e. that the atomic en- results. ergy levels are expressed as a mix of different configurations With the development of space-borne spectroscopy, to- due to the configuration interaction͒. Calculations have been gether with the possibility of obtaining high resolution spec- performed for temperatures between 5,000K and 100,000K tra for a wide wavelength range including X-rays not detect- for the F II spectral lines and between 10,000K and able from the Earth’s surface, the interest in such results is 300,000K for the F III spectral lines for electrons, protons increasing. For example the Low Energy Transmission Grat- and helium ions as perturbers. The F II W values generated ing ͑LETG͒ on board the X-ray space observatory CHAN- by protons and helium ions are up to 5-10 times smaller than DRA provides high quality spectra in the wavelength region the widths generated by electrons and show weak depen- between 5 and 140 Å , and contains a series of lines which dence on the temperature. The F II d values generated by can provide density and temperature diagnostics for rela- electrons, protons and helium ions are very small, except for tively hot and dense stellar plasmas. An analysis of the X-ray the multiplet No. 9, and are of the same magnitude. Similar high resolution spectrum of some stars shows spectra which conclusions can be obtained for the F III W and d values in may be rich in emission lines in the soft X-ray region, in- the multiplet No. 1. Very good agreement has been found cluding Si V lines. among our measured and calculated F II W and d values. Using a semiclassical perturbation approach, Milan S. Existing experimental W values also agree with the calcu- Dimitrijevic in collaboration with Nebil Ben Nessib and lated values. In the case of the F II d values our SCPF cal- Sylvie Sahal-Bre´chot, have obtained in 2004 Stark broaden- culations provide smaller values than those predicted by ing parameters for 16 Si V multiplets using atomic data cal- Griem ͑1974͒. The measured and calculated F III W values culated ab initio with the SUPERSTRUCTURE code. In or- agree mutually ͑within 5%). Measured F III d values show der to complete Stark broadening data for the most important evident scatter and within the experimental accuracy are charged perturbers in stellar atmospheres, Stark broadening practically equal to zero. The calculation provides a very parameters for protonϪ,HeIIϪ, and Si IIϪimpact line small negative shift which is practically independent on the widths and shifts are also presented. Results have been ob- electron temperature. tained for an electron density of 1017cmϪ3 as a function of The semiclassical perturbation formalism of Sylvie Sahal- temperature. Moreover, they have performed the same calcu- Bre´chot has been used in a series of papers for large scale lations with oscillator strengths calculated within the Cou- calculations of Stark broadening parameters for a number of lomb approximation. The differences, which are within the spectral lines of various emitters from neutral atoms up to 12 error bars of the semiclassical perturbation approach (Ϯ20 times ionized atoms. The results of such calculations are of Ϫ30%) confirm that the Bates & Damgaard approximation interest for a number of different problems in physics, astro- may be used to complete the atomic data set needed for the physics and plasma technology. In astrophysics, such atomic Stark broadening calculations for multicharged ions like Si data are of interest e.g. for numerical modelling of stellar V, where more reliable oscillator strength values are not atmospheres or abundance determinations, problems corre- available. lated with nucleogenesis, mixing between atmosphere and Data on the Stark broadening of neutral gallium spectral interior, stellar structure and evolution, and opacity calcula- lines are of interest not only for laboratory but also for as- tions. Moreover, Stark broadening parameters are of interest trophysical plasma research as e.g. for stellar spectra analysis for the investigation and diagnostics of laboratory and laser- and synthesis, for gallium abundance determination and produced plasmas, as well as for the theoretical studies of opacity calculations. Spectral lines of this element are regularities and systematic trends. present in the Solar spectrum. Moreover, for example Jas- In the case of four-times ionized atoms there exists a suf- chek and Jaschek have found in 1987 gallium lines not only ficiently complete set of the needed atomic data required for in the spectra of HgMn, Si-4200 and He-weak chemically sophisticated semiclassical calculations for a number of as- peculiar stars but also in the spectra of a few stars otherwise trophysically interesting lines. Therefore, large scale calcula- classified as normal. Dworetsky reports in 1993 on neutral tions have been performed with the semiclassical perturba- gallium lines in A-type star spectra, and Ryabchikova and tion formalism for C V, N V, O V, P V,SVandVV Smirnov in 1994 in the spectrum of HgMn star Kappa Can- spectral lines. When we did not have a sufficiently complete cri. Smith investigated in 1995 anomalous gallium line pro- set of reliable atomic data, the full semiclassical method files in HgMn stars and found evidence for chemical strati- could not be applied adequately, and simpler methods were fication in their atmospheres. To the astrophysical used for the calculation of C V, O V, F V, Ne V and Al V importance of gallium spectral lines, contributes the fact that Stark broadening parameters, including 6 multiplets of Si V. this element is often overabundant in chemically peculiar Such data are of interest for the consideration of radiative stars. Zverko and Zboril tried to derive in 1989 the gallium 32 ANNUAL REPORT abundance of 53 Tau from Ga I 4032.98 Å and 4172.06 Å of 1017 cmϪ3 and T ϭ 20,000K. Width value of Dimitrijevic spectral lines and Smith reports in 1996 on elemental abun- et al. ͑2004͒ is 0.257 Å and shift value 0.223 Å which is, dance of gallium in normal late-B and HgMn stars. In 1996 taking into account the simplicity of the method, excellent Smith concluded that HgMn stars have enhanced gallium for the width and within error bars for the shift. abundances, and Zboril and Berrington published in 2001 the In order to see the influence of Stark broadening mecha- Non-LTE gallium equivalent widths for the most prominent nism for Ga I spectral lines in stellar plasma conditions, gallium transitions as identified in real spectra and in ͑hot͒ Dimitrijevic et al. ͑2004͒ have calculated for their and mercury-manganese stars. Since around T ϭ 10,000K ͑which N’Dollo & Fabry ͑1987͒ results, Stark widths for an A type ϭ ϭ ͒ temperature is of particular interest for chemically peculiar star (Teff 10,000K, log g 4 atmosphere model and star atmospheres͒ hydrogen is mainly ionized, Stark broad- compared them with Doppler ones. Results obtained as a ening is the principal pressure broadening mechanism for function of the Rosseland optical depth show first of all, that such plasma conditions. photospheric layers exist where Doppler and Stark widths Milan S. Dimitrijevic, Miodrag Dacic and Zorica are comparable and where the Stark width is dominant which Cvetkovic in collaboration with Sylvie Sahal-Bre´chot calcu- is of interest to take into account when for example the strati- lated in 2004, using the semiclassical perturbation method fication of gallium across the stellar photosphere is consid- electron-, and proton-impact broadening parameters for 18 ered. Also, for transitions involving energy levels with Ga I transitions for perturber density of 1014cmϪ3, typical higher principal quantum numbers, the importance of Stark for stellar atmosphere conditions and temperatures from broadening mechanism increases. This is due to the fact that 2,500 up to 50,000K. N’Dollo and Fabry calculated in 1987 with the increase of the principal quantum number of the Stark widths for four Ga I multiplets ͑GaI 4p2PoϪ5s2S, upper level of the transition, the difference between this, and 5s2SϪ6p2Po,5s2SϪ7p2Po and 5p2PoϪ10s2S͒ using the the closest perturbing energy level decreases, resulting in the semiclassical theory of Griem, Baranger, Kolb and Oertel for increase of the Stark broadening influence. electron contribution and the quasistatic theory of Griem for The new experimental evaluations of Stark broadening ion contribution. They also obtained experimentally, observ- parameters for Ga I spectral lines, especially at higher tem- ing spectroscopically a potassium-gallium arc, Stark widths peratures, will be certainly of interest not only from the the- 2 o Ϫ 2 2 o Ϫ 2 oretical point of view but also for astrophysical and labora- for Ga I 4p P1/2 5s S1/2 4034.1 Å and 4p P3/2 5s S1/2 4173.2 Å spectral lines. Potassium-gallium mixture was used tory plasma diagnostics and modeling. as the cathode, while the plasma was initiated in the presence In 2004 Dragomir Olevic and Zorica Cvetkovic published of argon. If we compare the results obtained by Dimitrijevic the results of their work on the determination of binary star et al. ͑2004͒ with experimental and theoretical results of orbital elements. Such elements for 10 interferometric binary N’Dollo and Fabry, one can see that both calculations are in systems with no previous orbit determination are presented, ͑ ͒ agreement with experimental data within error bars. How- namely for: WDS 07143-2621 FIN 323 , WDS 12064-6543 ͑ ͒ ͑ ͒ ever, the temperature trend obtained by Dimitrijevic et al. FIN 367Aa , WDS 12446-5717 FIN 65 , WDS 13320-6519 ͑ ͒ ͑ ͒ ϩ ͑2004͒, diverges condiderably from the N’Dollo and Fabry FIN 369 , WDS 13574-6229 FIN 370 , WDS 14189 5452 ͑ ͒ ͑ ͒ result. One should note that in N’Dollo & Fabry, ion broad- CHR 137 , WDS 14373-4608 FIN 318 Aa , WDS 16115 ϩ ͑ ͒ ͑ ͒ ening contribution has been estimated within the Griem’s 0943 FIN 354 , WDS 17018-5108 I 1306 , WDS 17221- ͑ ͒ quasistatic approach Comparing calculated values of 7007 FIN 373 . Also, the improved method used ͑ ´͒ N’Dollo and Fabry with electron broadening and with elec- Koval’skij-Olevic , is briefly described. tron ϩ ion broadening, one can see that within this approach In spite of difficulties met in the calculation of the orbital elements of the selected pairs, such as short arcs covered the obtained contribution of ion broadening is negligible. with observations, large gaps between two consecutive However, if the impact approximation is valid, the result is groups of observations and high inclinations, they obtained different. elements with small relative errors. Contributing to this was, Since ionization potentials of Ga, K and Ar are 6.00 eV, on the one hand, enhanced accuracy of measurements thanks 4.339 eV and 15.755 eV respectively, the most appropriate to the use of new techniques and, on the other, the KOVOLE way to estimate the influence of ion-impact broadening for method employed. the considered experiment is to compare electron-impact The obtained orbital elements are preliminary ones. In widths with widths due to impacts with ions of electron do- view of the relatively short periods these systems should nors potassium and gallium. Dimitrijevic et al. ͑2004͒ ob- more often be included in interferometric observational pro- tained that the ion contribution is around 20%. N’Dollo and grams. By doing so, we might in the near future, obtain Fabry obtained their result for electron densities between 10 definite orbital elements. As these systems have their trigo- 14cmϪ3 and2x1015cmϪ3 and scaled and presented them on nometric parallaxes already determined by the Hipparcos 1016cmϪ3, where the impact approximation is not valid. mission, the sums of their masses may be determined. This is However, since for some experimental densities this approxi- particularly important because the greater part ͑seven͒ of mation is valid the ion broadening contribution is probably these systems, according to their spectral type, belong to the underestimated. main sequence. Lakic´evic´ estimated in 1983 Stark broadening parameters for Ga I 4p2PoϪ5s2S multiplet on the basis of regularities PUBLICATIONS and systematic trends and he obtained that W is 0.30 Å and Petrosian, A.R., Allen, R., Leitherer, C., MacKenty, J., the absolute value of the shift 0.16 Å for an electron density McLean, B. & Panagia, N., 2003, ‘‘Studies of the Second ISAAC NEWTON INSTITUTE OF CHILE 33

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