DOCSLIB.ORG

The Optical Gravitational Lensing Experiment. Planetary and Low

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Optical Gravitational Lensing Experiment. Planetary and Low 1 The Optical Gravitational Lensing Experiment. Planetary and Low-Luminosity Object Transits in the Fields of Galactic Disk. Results of the 2003 OGLE Observing Campaigns∗ A. Udalski1, M.K. Szyma´nski1, M. Kubiak1, G. Pietrzy´nski1,2, I. Soszy´nski1,2, K. Z˙ e b r u ´n1, O. Szewczyk1, andL. Wyrzykowski1 1Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland e-mail: (udalski,msz,mk,pietrzyn,soszynsk,zebrun,szewczyk,wyrzykow)@astrouw.edu.pl 2 Universidad de Concepci´on, Departamento de Fisica, Casilla 160–C, Concepci´on, Chile ABSTRACT We present results of two observing campaigns conducted by the OGLE-III survey in the 2003 observing season aiming at the detection of new objects with planetary transiting companions. Six fields of 35′ × 35′ each located in the Galactic disk were monitored with high frequency for several weeks in February–July 2003. Additional observations of three of these fields were also collected in the 2004 season. Altogether about 800 and 1500 epochs were collected for the fields of both campaigns, respectively. The search for low depth transits was conducted on about 230 000 stars with photometry better than 15 mmag. It was focused on detection of planetary companions, thus clear non- planetary cases were not included in the final list of selected objects. Altogether we discovered 40 stars with shallow (≤ 0.05 mag) flat-bottomed transits. In each case several individual transits were observed allowing determination of photometric elements. Additionally, the lower limits on radii of the primary and companion were calculated. From the photometric point of view the new OGLE sample contains many very good candidates for extrasolar transiting planets. However, only the future spectroscopic follow-up observations of the OGLE sample – determination of the amplitude of radial velocity and exclusion of blending possibilities – may allow to confirm their planetary status. In general, the transiting objects may be extrasolar planets, brown dwarfs, M-type dwarfs or fake transits arXiv:astro-ph/0411543v2 7 Jan 2005 caused by blending. All photometric data of objects with transiting companions discovered during the 2003 campaigns are available to the astronomical community from the OGLE Internet archive. 1. Introduction Detection of planetary transits in the spectroscopically discovered extrasolar planetary system HD209458 (Henry et al. 1999, Charbonneau et al. 1999) em- pirically proved that the photometric method of detection of extrasolar planets, called the “transit method”, can be a potentially important tool in planetary ∗Based on observations obtained with the 1.3 m Warsaw telescope at the Las Campanas Observatory of the Carnegie Institution of Washington. 2 searches. However, in spite of many efforts no extrasolar planet was detected in this manner during the next few years. The transit method offers many advan- tages compared to the traditional spectroscopic method. When the photometric observations are combined with precise spectroscopy all important parameters of a planet like its size and mass can be derived providing extremely important data to studying in detail the structure of planets and evolution of extrasolar planetary systems. In 2002 the Optical Gravitational Lensing Experiment (OGLE) survey announ- ced results of two photometric campaigns aimed at photometric discovery of low depth transits caused by extrasolar planets or other sort of “low-luminosity” objects (Udalski et al. 2002abc, 2003). About 140 stars such stars were found among about 150 000 stars in two lines-of-sight in the Galactic disk – toward the Galactic center and the constellation of Carina. It was obvious from the very beginning that the significant part of the discovered transits may be caused by stellar size companions, part can be an effect of blending of eclipsing stars with bright unresolvable neighbors while in the small number of objects the transits could be of planetary origin. Unfortunately, the photometry, which allows de- termination of size, cannot unambiguously distinguish planetary or brown dwarf from late M-type dwarf stellar companions as all of them may have the radii of the order of 0.1–0.2 R⊙ (1–2 RJup). The OGLE transiting objects were subject of many follow up studies in the past two years. The most important follow up observations of the OGLE ob- jects were high resolution spectroscopic observations for radial velocity changes. In the past two years the planetary status of four of the OGLE transiting com- panions was confirmed by measuring small amplitude radial velocity variation with the same period and in appropriate phase as resulting from the OGLE photometric orbits: OGLE-TR-56 (Konacki et al. 2003a, Torres et al. 2004a, Bouchy et al. 2004b), OGLE-TR-113 (Bouchy et al. 2004a, Konacki et al. 2004), OGLE-TR-132 (Bouchy et al. 2004a) and OGLE-TR-111 (Pont et al. 2004). An- other OGLE object – OGLE-TR-10 – also very likely hosts an extrasolar planet although additional radial velocity observations are necessary to fully confirm its planetary status (Konacki et al. 2003b, Bouchy et al. 2004b). Additionally, the high resolution spectroscopy allowed to rule out possible blending scenarios making the confirmations very reliable and sound. It is worth noting that except for OGLE-TR-132, which was at the edge of detection, all the remaining OGLE planets were on the OGLE short lists of the most likely planetary candidates based on their photometric properties. The sixth known extrasolar transiting planet, TrES-1, has recently been found by the small telescope wide field TrES survey (Alonso et al. 2004). Detection of the first transiting planets allowed to significantly increase the sample of extrasolar planets with precisely known masses and radii, thus pro- viding crucial empirical data for testing the planetary models etc. Surprisingly the first three OGLE planets (OGLE-TR-56, OGLE-TR-113 and OGLE-TR- 132) turned out to form a new class of “very hot Jupiters” – giant planets orbiting their hosts stars with periods shorter than 2 days. Such systems have been unknown so far in the solar neighborhood. It is clear that the detection 3 of additional transiting planets is of high importance for extrasolar planetary science. In 2003 the OGLE survey conducted two additional observational campaigns aimed at the detection of additional transiting exoplanets. Altogether six new fields located in the Galactic disk in the constellations of Carina, Centaurus and Musca were monitored regularly with high time resolution for a few weeks each. The search for objects with transiting companions was performed in similar manner as in the past campaigns. However, it was more focused on planetary transits. Hence, many clear detections of low mass stellar transiting companions were removed from the final sample of objects with transiting companions. Similarly to our previous transit samples (Udalski et al. 2002abc, 2003) the photometric data of our new objects with transiting companions from the 2003 fields can be found in the OGLE Internet archive. Thus the follow-up spectroscopic observations and confirmation of their planetary or non-planetary status can be made in short time scale. Details and pointers to the OGLE Internet archive can be found at the end of this paper. 2. Observational Data Observations presented in this paper were collected with the 1.3-m Warsaw telescope at the Las Campanas Observatory, Chile (operated by the Carnegie Institution of Washington), equipped with a wide field CCD mosaic camera. The camera consists of eight 2048 × 4096 pixel SITe ST002A detectors. The pixel size of each of the detectors is 15 µm giving the 0.26 arcsec/pixel scale at the focus of the Warsaw telescope. Full field of view of the camera is about 35′ × 35′. The gain of each chip is adjusted to be about 1.3 e−/ADU with the readout noise of about 6 to 9 e−, depending on the chip. More details on the instrumental setup can be found in Udalski (2003). Two observing campaigns were conducted in 2003. The first of them – OGLE campaign #3 – started on February 12, 2003 and lasted up to March 26, 2003. The photometric data were collected during 39 nights spanning 43 days. Three fields of the Galactic disk were observed continuously with the time resolution of about 15 minutes. Acronyms and equatorial coordinates of these fields are provided in Table 1. The second campaign – OGLE campaign #4 – started on March 25, 2003. While the main observing material was collected to the middle of May 2003, the fields were also observed from time to time until July, 25, 2003. Moreover, additional but less extensive photometric monitoring of the campaign #4 fields was conducted during the 2004 observing season – from March 14, 2004 up to July 30, 2004. As in the previous campaigns three fields of the Galactic disk were continuously monitored with the time resolution of about 15 minutes. Details on the location of these fields and their acronyms can also be found in Table 1. All observations were made through the I-band filter. The exposure time of each image was set to 180 seconds. Altogether about 820 images were collected for each field during our OGLE campaign #3 and 1050 images in 2003 plus 460 4 Table1 Equatorial coordinates of the observed fields Field RA (J2000) DEC (J2000) Campaign #3 CAR106 11h03m00s −61◦50′00′′ CEN106 11h32m30s −60◦50′00′′ CEN107 11h54m00s −62◦00′00′′ Campaign #4 CEN108 13h33m00s −64◦15′00′′ MUS100 13h15m00s −64◦51′00′′ MUS101 13h25m00s −64◦58′00′′ images in 2004 for the campaign #4 fields. The median seeing of images in both campaigns was about 1.′′2. 3. Data Reductions All collected images were preprocessed (de-biasing and flat-fielding) in real time with the standard OGLE-III data pipeline (Udalski 2003). Photometric reductions of the 2003 season images were performed off-line af- ter the end of both campaigns.
Load more

Recommended publications
  • The Extreme Luminosity States of Sagittarius A*
    A&A 512, A2 (2010) Astronomy DOI: 10.1051/0004-6361/200913186 & c ESO 2010 Astrophysics The extreme luminosity states of Sagittarius A* N. Sabha1, G. Witzel1,A.Eckart1,2, R. M. Buchholz1,M.Bremer1, R. Gießübel2,1, M. García-Marín1, D. Kunneriath1,2,K.Muzic1, R. Schödel3, C. Straubmeier1, M. Zamaninasab2,1, and A. Zernickel1 1 I.Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany e-mail: [sabha;witzel;eckart]@ph1.uni-koeln.de 2 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany 3 Instituto de Astrofísica de Andalucía (CSIC), Camino Bajo de Huétor 50, 18008 Granada, Spain e-mail: [email protected] Received 26 August 2009 / Accepted 22 December 2009 ABSTRACT We discuss mm-wavelength radio, 2.2–11.8 μm NIR and 2–10 keV X-ray light curves of the super massive black hole (SMBH) coun- terpart of Sagittarius A* (SgrA*) near its lowest and highest observed luminosity states. We investigate the structure and brightness of the central S-star cluster harboring the SMBH to obtain reliable flux density estimates of SgrA* during its low luminosity phases. We then discuss the physical processes responsible for the brightest flare as well as the faintest flare or quiescent emission in the NIR and X-ray domain. To investigate the low state of SgrA* we use three independent methods to remove or strongly suppress the flux density contributions of stars in the central 2 diameter region around SgrA*. The three methods are: a) low-pass filtering the image; b) iterative identification and removal of individual stars; c) automatic point spread function (PSF) subtraction.
    [Show full text]
  • Detection of the Schwarzschild Precession in the Orbit of the Star S2 Near the Galactic Centre Massive Black Hole GRAVITY Collaboration:? R
    A&A 636, L5 (2020) Astronomy https://doi.org/10.1051/0004-6361/202037813 & c GRAVITY Collaboration 2020 Astrophysics LETTER TO THE EDITOR Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole GRAVITY Collaboration:? R. Abuter8, A. Amorim6,13, M. Bauböck1, J. P. Berger5,8, H. Bonnet8, W. Brandner3, V. Cardoso13,15, Y. Clénet2, P. T. de Zeeuw11,1, J. Dexter14,1, A. Eckart4,10;??, F. Eisenhauer1, N. M. Förster Schreiber1, P. Garcia7,13, F. Gao1, E. Gendron2, R. Genzel1,12;??, S. Gillessen1;??, M. Habibi1, X. Haubois9, T. Henning3, S. Hippler3, M. Horrobin4, A. Jiménez-Rosales1, L. Jochum9, L. Jocou5, A. Kaufer9, P. Kervella2, S. Lacour2, V. Lapeyrère2, J.-B. Le Bouquin5, P. Léna2, M. Nowak17,2, T. Ott1, T. Paumard2, K. Perraut5, G. Perrin2, O. Pfuhl8,1, G. Rodríguez-Coira2, J. Shangguan1, S. Scheithauer3, J. Stadler1, O. Straub1, C. Straubmeier4, E. Sturm1, L. J. Tacconi1, F. Vincent2, S. von Fellenberg1, I. Waisberg16,1, F. Widmann1, E. Wieprecht1, E. Wiezorrek1, J. Woillez8, S. Yazici1,4, and G. Zins9 (Affiliations can be found after the references) Received 25 February 2020 / Accepted 4 March 2020 ABSTRACT The star S2 orbiting the compact radio source Sgr A* is a precision probe of the gravitational field around the closest massive black hole (candidate). Over the last 2.7 decades we have monitored the star’s radial velocity and motion on the sky, mainly with the SINFONI and NACO adaptive optics (AO) instruments on the ESO VLT, and since 2017, with the four-telescope interferometric beam combiner instrument GRAVITY.
    [Show full text]
  • An Update on Monitoring Stellar Orbits in the Galactic Center S
    Draft version November 29, 2016 Preprint typeset using LATEX style emulateapj v. 5/2/11 AN UPDATE ON MONITORING STELLAR ORBITS IN THE GALACTIC CENTER S. Gillessen1, P.M. Plewa1, F. Eisenhauer1, R. Sari2, I. Waisberg1, M. Habibi1, O. Pfuhl1, E. George1, J. Dexter1, S. von Fellenberg1, T. Ott1, R. Genzel1,3 Draft version November 29, 2016 ABSTRACT Using 25 years of data from uninterrupted monitoring of stellar orbits in the Galactic Center, we present an update of the main results from this unique data set: A measurement of mass of and distance to Sgr A*. Our progress is not only due to the eight year increase in time base, but also due to the improved definition of the coordinate system. The star S2 continues to yield the best 6 constraints on the mass of and distance to Sgr A*; the statistical errors of 0:13 × 10 M and 0:12 kpc have halved compared to the previous study. The S2 orbit fit is robust and does not need any prior information. Using coordinate system priors, also the star S1 yields tight constraints on mass and distance. For a combined orbit fit, we use 17 stars, which yields our current best estimates for mass 6 and distance: M = 4:28 ± 0:10jstat: ± 0:21jsys × 10 M and R0 = 8:32 ± 0:07jstat: ± 0:14jsys kpc. These numbers are in agreement with the recent determination of R0 from the statistical cluster parallax. The positions of the mass, of the near-infrared flares from Sgr A* and of the radio source Sgr A* agree to within 1 mas.
    [Show full text]
  • February 8, 2001 DUKE DAYS EVENTS CALENDAR TABLE of CONTENTS
    AN ODE (AND A JAB) TO THE XFL PAGE 22 --sssssr FEB08 2001 THURSDAY FKBRI ARY 8, 2001 VOL. 78, No. 34 reezeJames Madison University Jazzin' It Up Keeping Track Oh, The Places They'll Go JMU jazz is keeping the beat in Like a Prayer and around Harrisonburg The men's and women's track Senior dance majors to show- demonstrating their talent and teams had numerous qualifiers for Sunday's Prayer and Praise event case the skill they'll take to the the IC4A and ECAC Championships, delighting audiences. united more than 500 students of world after JMU. Page 14 respectively, at the Penn State and different denominations. Page 3 Page 13 Patriot Games. Page 19 Campus Shooting victim stable peeping Non-student suspect still at-large after Hunters Ridge violence BY TOM SIMMII m black male between 5 leet lo hut declined comment on the Hunters Ridge news editor inches and 5 feet 11 inches tall. call's origin. He was not aware persists Whitelow was not present of prior problems at Fields and A JMU student shot once in when pottn arrived, and the Whitelow s residence. l k key the l best in his Hunters Ridge HI'O is not certain how he (led Boshart said he did not Three incidents apartment is m good oandttson the enme scene, Boshart said. think that Whitelow had a I after .in reported argument lioslurt said, barges against prior record with the HPD. He reported in week duringiiiirirn, tl.i cardi,m game Sunday Whitelow will be in reference said he did not know if drugs night.
    [Show full text]
  • Supplementary Materials For
    www.sciencemag.org/cgi/content/full/338/6103/84/DC1 Supplementary Materials for The Shortest-Known–Period Star Orbiting Our Galaxy's Supermassive Black Hole L. Meyer, A. M. Ghez,* R. Schödel, S. Yelda, A. Boehle, J. R. Lu, T. Do, M. R. Morris, E. E. Becklin, K. Matthews *To whom correspondence should be addressed. E-mail: [email protected] Published 5 October 2012, Science 338, 84 (2012) DOI: 10.1126/science.1225506 This PDF file includes: Materials and Methods Supplementary Text Figs. S1 and S2 Tables S1 to S5 References (35–42) Materials and Methods Image construction Images are constructed from the speckle data sets by both shift-and-add (SAA), which has been our approach in the past (37, 38, 7), and Speckle holography, which is a new and more effective approach for this data set (39). In SAA, the images are registered based on the positions of the brightest speckle in the PSF of the short-exposure images (40). We implemented this approach similarly to past analyses of these data sets (7, 37), except for our use of a new distortion solution for NIRC (35). While the advantage of this approach is its computational efficiency as well as its robust treatment of edge- effects, the disadvantage is that information in all but the brightest speckle is not only lost but becomes a source of noise in a large, so-called “seeing-halo”. To reduce the size of the seeing-halo, only frames with the minimum number of speckles are used. In spite of discarding photons, frame selection increases the overall dynamic range of the images because it is limited mainly by stellar crowding and the halos around the brighter stars.
    [Show full text]
  • Stellar Motion Near the Supermassive Black Hole in the Galactic Center
    Stellar Motion Near the Supermassive Black Hole in the Galactic Center INAUGURAL-DISSERTATION zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultät der Universität zu Köln vorgelegt von Marzieh Parsa aus Shiraz, Iran Köln 2018 Berichterstatter: Prof. Dr. Andreas Eckart Prof. Dr. J. Anton Zensus Tag der mündlichen Prüfung: 10. Oktober 2017 Abstract General relativity is the least tested theory of physics. The close environment of the supermassive black hole provides us with the perfect laboratory for the investigation of the predictions of this theory. Therefore, the Observation of S-stars in the Galactic center in the near-infrared wavelengths provides the opportunity to study the physics in the vicinity of a supermassive black hole and conduct unique dynamical tests of the theory of general relativity. In my thesis, I use near-infrared high angular resolution adaptive optics images of the central stellar cluster acquired with the NACO instrument at the Very Large Telescope of the European Southern Observatory, from 2002 to 2015. In addition, I employ the published astrometric and line of sight velocity data obtained with the Keck telescope from 1995 to 2013. I use the SiO maser sources in the wide field of view of the NACO S27 camera. The positions and motions of these maser sources and the position of Sgr A*, the supermassive black hole in the center of the Galaxy, is known in the radio regime. Therefore, I find the connection between the near-infrared data and the radio reference frame. Next, I connect the images of the S27 camera to the images of the S13 camera, in which the S-stars are observable in the central arcsecond, using six overlap stars.
    [Show full text]
  • Pos(FRAPWS2018)050 , E
    Light and shadow in the Galactic Center On the detection of the relativistic periastron shift of star S2 in the Galactic Center Andreas Eckart1;2∗, M. Parsa1;2, E. Mossoux3 B. Shahzamanian1;4, M. Zajacek1;2, E. PoS(FRAPWS2018)050 Hosseini1;2, M. Subroweit1, F. Peissker1, N. Sabha1, M. Valencia-S.1, C. Straubmeier1, V. Karas5, S. Britzen2, A. Zensus2 1) I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany; 2) Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany; 3)Space sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, Allée du 6 Août, 19c, Bât B5c, 4000 Liège, Belgium; 4) Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia s/n, 18008 Granada, Spain 5) Astronomical Institute of the Academy of Sciences Prague, Bocni II 1401/1a, CZ-141 31 Praha 4, Czech Republic E-mail: [email protected] We report on the nature of prominent sources of light and shadow in the Galactic Center. With respect to the Bremsstrahlung X-ray emission of the hot plasma in that region the Galactic Center casts a ’shadow’. The ’shadow’ is caused by the Circum Nuclear Disk that surrounds SgrA* at a distance of about 1 to 2 parsec. This detection allows us to do a detailed investigation of the physical properties of the surroundings of the super massive black hole. Further in, the cluster of high velocity stars orbiting the central super massive black hole SgrA* represents an ideal probe for the gravitational potential and the degree of relativity that one can attribute to this area.
    [Show full text]
  • Arxiv:2008.04764V1 [Astro-Ph.GA] 11 Aug 2020
    Draft version August 12, 2020 Typeset using LATEX twocolumn style in AASTeX63 S62 and S4711: Indications of a population of faint fast moving stars inside the S2 orbit S4711 on a 7.6 year orbit around Sgr A* Florian Peiβker ,1 Andreas Eckart ,1, 2 Michal Zajacekˇ ,3, 1 Basel Ali,1 and Marzieh Parsa1 1I.Physikalisches Institut der Universit¨atzu K¨oln, Z¨ulpicherStr. 77, 50937 K¨oln,Germany 2Max-Plank-Institut f¨urRadioastronomie, Auf dem H¨ugel69, 53121 Bonn, Germany 3Center for Theoretical Physics, Al. Lotnikw 32/46, 02-668 Warsaw, Poland (Received June 1, 2019; Revised January 10, 2019; Accepted August 12, 2020) Submitted to ApJ ABSTRACT We present high-pass filtered NACO and SINFONI images of the newly discovered stars S4711- S4715 between 2004 and 2016. Our deep H+K-band (SINFONI) and K-band (NACO) data shows the S-cluster star S4711 on a highly eccentric trajectory around Sgr A* with an orbital period of 7.6 years and a periapse distance of 144 AU to the super massive black hole (SMBH). S4711 is hereby the star with the shortest orbital period and the smallest mean distance to the SMBH during its orbit to date. The used high-pass filtered images are based on co-added data sets to improve the signal to noise. The spectroscopic SINFONI data let us determine detailed stellar properties of S4711 like the mass and the rotational velocity. The faint S-cluster star candidates, S4712-S4715, can be observed in a projected distance to Sgr A* of at least temporarily ≤ 120 mas.
    [Show full text]
  • The Shortest Known Period Star Orbiting Our Galaxy's Supermassive
    The Shortest Known Period Star Orbiting our Galaxy’s Supermassive Black Hole L. Meyer,1 A. M. Ghez,1∗ R. Schodel,¨ 2 S. Yelda,1 A. Boehle,1 J. R. Lu,3 T. Do,4;5 M. R. Morris,1 E. E. Becklin,1 K. Matthews6 1University of California Los Angeles, Department of Physics and Astronomy, Los Angeles, CA 90095-1547, USA 2Instituto de Astrof´ısica de Andaluc´ıa (CSIC), Glorieta de la Astronomia S/N, 18008 Granada, Spain 3University of Hawaii, Institute for Astronomy, Honolulu, HI 96822, USA 4University of California Irvine, Department of Physics and Astronomy, Irvine, CA 92697-4575, USA 5Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto M5S 3H4, Ontario, Canada; Dunlap Fellow 6California Institute of Technology, Division of Mathematics, Physics and Astronomy, Pasadena, CA 91125, USA ∗To whom correspondence should be addressed; E-mail: [email protected] Stars with short orbital periods at the center of our galaxy offer a powerful and unique probe of a supermassive black hole. Over the past 17 years, the W. M. Keck Observatory has been used to image the Galactic center at the arXiv:1210.1294v1 [astro-ph.GA] 4 Oct 2012 highest angular resolution possible today. By adding to this data set and ad- vancing methodologies, we have detected S0-102, a star orbiting our galaxy’s supermassive black hole with a period of just 11.5 years. S0-102 doubles the number of stars with full phase coverage and periods less than 20 years. It thereby provides the opportunity with future measurements to resolve degen- 1 eracies in the parameters describing the central gravitational potential and to test Einstein’s theory of General Relativity in an unexplored regime.
    [Show full text]
  • Relativistic Effects in Orbital Motion of the S-Stars at the Galactic Center
    universe Article Relativistic Effects in Orbital Motion of the S-Stars at the Galactic Center Rustam Gainutdinov 1,2,* and Yurij Baryshev 2* 1 SPb Branch of Special Astrophysical Observatory of Russian Academy of Sciences, 65 Pulkovskoye Shosse, 196140 St. Petersburg, Russia 2 Astrophysics Department, Mathematics & Mechanics Faculty, Saint Petersburg State University, 28 Universitetskiy Prospekt, 198504 St. Petersburg, Russia * Correspondence: [email protected] (R.G.); [email protected] (Y.B.) Received: 19 September 2020; Accepted: 8 October 2020; Published: 14 October 2020 Abstract: The Galactic Center star cluster, known as S-stars, is a perfect source of relativistic phenomena observations. The stars are located in the strong field of relativistic compact object Sgr A* and are moving with very high velocities at pericenters of their orbits. In this work we consider motion of several S-stars by using the Parameterized Post-Newtonian (PPN) formalism of General Relativity (GR) and Post-Newtonian (PN) equations of motion of the Feynman’s quantum-field gravity theory, where the positive energy density of the gravity field can be measured via the relativistic pericenter shift. The PPN 00 parameters b and g are constrained using the S-stars data. The positive value of the Tg component of the gravity energy–momentum tensor is confirmed for condition of S-stars motion. Keywords: Parameterized Post-Newtonian formalism; relativistic celestial mechanics; Galactic Center 1. Introduction The S-stars cluster in the Galactic Center [1–4] is a unique observable object to investigate. Once for the orbital period, the stars pass their pericenters, where they reach high velocities ( 0.01 or even 0.1 ∼ ∼ of the speed of light for the most recent discovered stars [5]) and get close to the relativistic compact object Sgr A*.
    [Show full text]
  • Detection of Faint Stars Near Sagittarius A* with GRAVITY R
    Detection of faint stars near Sagittarius A* with GRAVITY R. Abuter, A. Amorim, M. Bauböck, J.P. Berger, H. Bonnet, W. Brandner, Y. Clénet, Y. Dallilar, R. Davies, P.T. de Zeeuw, et al. To cite this version: R. Abuter, A. Amorim, M. Bauböck, J.P. Berger, H. Bonnet, et al.. Detection of faint stars near Sagit- tarius A* with GRAVITY. Astron.Astrophys., 2021, 645, pp.A127. 10.1051/0004-6361/202039544. hal-03171389 HAL Id: hal-03171389 https://hal.archives-ouvertes.fr/hal-03171389 Submitted on 17 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A&A 645, A127 (2021) Astronomy https://doi.org/10.1051/0004-6361/202039544 & c GRAVITY Collaboration 2021 Astrophysics Detection of faint stars near Sagittarius A* with GRAVITY GRAVITY Collaboration?: R. Abuter8, A. Amorim6,12, M. Bauböck1, J. P. Berger5,8, H. Bonnet8, W. Brandner3, Y. Clénet2, Y. Dallilar1, R. Davies1, P. T. de Zeeuw10,1, J. Dexter13,1, A. Drescher1,16, F. Eisenhauer1, N. M. Förster Schreiber1, P. Garcia7,12, F. Gao1,??, E. Gendron2, R. Genzel1,11, S. Gillessen1, M. Habibi1, X. Haubois9, G. Heißel2, T.
    [Show full text]
  • Investigating the Relativistic Motion of the Stars Near the Supermassive Black Hole in the Galactic Center
    Draft version July 12, 2017 Typeset using LATEX twocolumn style in AASTeX61 INVESTIGATING THE RELATIVISTIC MOTION OF THE STARS NEAR THE SUPERMASSIVE BLACK HOLE IN THE GALACTIC CENTER M. Parsa,1, 2 A. Eckart,1, 2 B. Shahzamanian,1 V. Karas,3 M. Zajacek,ˇ 1, 2 J. A. Zensus,2 and C. Straubmeier1 1I. Physikalisches Institut, Universit¨atzu K¨oln, Z¨ulpicherStr. 77, 50937 K¨oln,Germany 2Max-Planck-Institut f¨urRadioastronomie, Auf dem H¨ugel69, 53121 Bonn, Germany 3Astronomical Institute, Academy of Science, Boˇcn´ıII 1401, CZ-14131 Prague, Czech Republic (Received April 27, 2017; Accepted June 23, 2017) Submitted to ApJ ABSTRACT The S-star cluster in the Galactic center allows us to study the physics close to a supermassive black hole including distinctive dynamical tests of general relativity. Our best estimates for the mass of and the distance to Sgr A* using 6 the three shortest period stars (S2, S38, and S55/S0-102) and Newtonian models are MBH = 4:15 ± 0:13 ± 0:57 × 10 M and R0 = 8:19±0:11±0:34 kpc. Additionally, we aim at a new and practical method to investigate the relativistic orbits of stars in the gravitational field near Sgr A*. We use a first-order post-Newtonian approximation to calculate the stellar orbits with a broad range of periapse distance rp. We present a method that employs the changes of orbital elements derived from elliptical fits to different sections of the orbit. These changes are correlated with the relativistic parameter defined as Υ ≡ rs=rp (with rs being the Schwarzschild radius) and can be used to derive Υ from observational data.
    [Show full text]