DOCSLIB.ORG

The Star Clusters Young & Old Newsletter

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

SCYON The Star Clusters Young & Old Newsletter edited by Holger Baumgardt, Ernst Paunzen and Pavel Kroupa SCYON can be found at URL: http://astro.u-strasbg.fr/scyon SCYONIssueNo.31 11December2006 EDITORIAL Here is the 31st issue of the SCYON newsletter. The current issue contains 35 abstracts, an an- nouncement for a new, parallel N-body code and announcements for conferences in Italy, Germany and Armenia. It also contains job advertisements for postdoctoral and tenure track positions from Rochester Institute of Technology. We wish everybody a merry holiday season and a happy new year 2007 and thank those who sent us their contributions. Holger Baumgardt, Ernst Paunzen and Pavel Kroupa ................................................... ................................................. CONTENTS Editorial .......................................... ...............................................1 SCYON policy ........................................ ...........................................2 Mirror sites ........................................ ..............................................2 Abstract from/submitted to REFEREED JOURNALS ........... ................................3 1. Star Forming Regions ............................... ........................................3 2. Embedded Clusters................................. .........................................7 3. Galactic Center Clusters........................... ..........................................9 4. Galactic Open Clusters............................. ........................................10 5. Galactic Globular Clusters ......................... ........................................14 6. Extragalactic Clusters............................ ..........................................20 7. Dynamical evolution - Simulations. .......................................24 8. Miscellaneous.................................... ..........................................30 Abstracts of CONFERENCE PROCEEDINGS ................... ...............................31 Ph.D. (dissertation) summaries ....................... ...........................................38 Conference / announcements........................... ..........................................39 Jobs ............................................... .............................................46 2 SCYON POLICY The SCYON Newsletter publishes abstracts from any area in astronomy which are relevant to research on star clusters. We welcome all contributions. Topics to be covered include 1. Abstracts from refereed articles 2. Abstracts from conference proceedings 3. PhD summaries 4. General announcements : Conferences, new databases, and the likes. Concerning possible infringements to copyright laws, we understand that the authors themselves are taking responsibility for the material they send us. We make no claim whatsoever to owning the material that is posted at our url or circulated by email. The newsletter SCYON is a free service. It does not substitute for our personal opinions, nor does it reflect in any way the views of our respective institutes of affiliations. SCYON will be published initially once every two months. If the number of contributions justi- fies monthly installments, we will move toward more frequent issues in order to keep the newsletter relatively short, manageable for us, and up-to-date. Conference and journal abstracts can be submitted at any time either by web download, or failing this, we also accept abstracts typeset using the latest latex abstract template (available from the SCYON webpage). We much prefer contributors to use the direct download form, since it is mostly automated. Abstracts will normally appear on the website as soon as they are submitted to us. Other contributions, such as PhD summaries, should be sent to us using the LaTeX template. Please do not submit postscript files, nor encoded abstracts as e-mail attachments. All abstracts/contributions will be processed, but we reserve the right to not post abstracts sub- mitted in the wrong format or which do not compile. If you experience any sort of problems accessing the web site, or with the LaTeX template, please write to us at [email protected]. A “Call for abstracts” is sent out approximately one week before the next issue of the newsletter is finalised. This call contains the deadline for abstract submissions for that coming issue and the LaTeX abstract template. Depending on circumstances, the editors might actively solicit contributions, usually those spotted on a preprint server, but they do not publish abstracts without the author’s consent. We implicitly encourage further dissemination of the letter to institutes and astronomers who may benefit from it. The editors SCYON Mirrors The official Scyon mirror site in Australia is hosted at the Centre for Astrophysics & Supercomputing of the University of Swinburne by Duncan Forbes and his team : http://astronomy.swin.edu.au/scyon/) ABSTRACTS FROM REFEREED JOURNALS 3 1. Star Forming Regions Current Star Formation in the Perseus Molecular Cloud: Constraints from Unbiased Submillimeter and Mid-Infrared Surveys Jes K. Jørgensen (1), Doug Johnstone (2,3), Helen Kirk (3,2), & Philip C. Myers (1) (1) Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS42, Cambridge, MA 02138, USA, (2) Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7, Canada, (3) Department of Physics & Astronomy, University of Victoria, Victoria, BC, V8P 1A1, Canada We present a census of the population of deeply embedded young stellar objects (YSOs) in the Perseus molecular cloud complex based on a combination of Spitzer Space Telescope mid-infrared data from the “Cores to Disks” (c2d) legacy team and JCMT/SCUBA submillimeter maps from the COMPLETE team. The mid-infrared sources detected at 24 µm and having [3.6] − [4.5] > 1 are located close to the center of the SCUBA cores, typically within 15′′ of their peaks. The narrowness of the spatial distribution of mid-infrared sources around the peaks of the SCUBA cores suggests that no significant dispersal of the newly formed YSOs has occurred. This argues against the suggestion that motions of protostars regulate the time scales over which significant (Bondi-Hoyle) accretion can occur. The YSOs are found to have red [3.6] − [4.5] and [8.0] − [24] colors, but not comparable red [5.8]−[8.0] colors. The most deeply embedded YSOs are found in regions with high extinction, AV ≥ 5, similar to the extinction threshold observed for the SCUBA cores. All the SCUBA cores with high concentrations have embedded YSOs, but not all cores with low concentrations are starless. From the above considerations a relatively unbiased sample of 49 deeply embedded YSOs is constructed. Embedded YSOs are found in 40 of the 72 SCUBA cores with only three cores harboring multiple embedded YSOs within 15′′. The equal number of SCUBA cores with and without embedded YSOs suggests that the time scale for the evolution through the dense prestellar stages, where the cores are recognized in the submillimeter maps and have central densities of 5 × 104 − 1 × 105∼cm−3, is similar to the time scale for the embedded protostellar stages. The current star formation efficiency of cores is estimated to be approximately 10–15%. In contrast, the star formation efficiency averaged over the cloud life time and compared to the total cloud mass is only a few percent, reflecting also the efficiency in assembling cloud material into the dense cores actually forming stars. To appear in : (astro-ph/0610381) For preprints, contact [email protected] Also available from the URL http://arxiv.org/abs/astro-ph/0610381 or by anonymous ftp at ................................................... ................................................. ABSTRACTS FROM REFEREED JOURNALS 4 A kinematic study of the Taurus-Auriga T association Claude Bertout & Francoise Genova Institut d’Astrophysique de Paris Observatoire de Strasbourg Aims: This is the first paper in a series dedicated to investigating the kinematic properties of nearby associations of young stellar objects. Here we study the Taurus-Auriga association, with the primary objective of deriving kinematic parallaxes for individual members of this low-mass star-forming region. Methods: We took advantage of a recently published catalog of proper motions for pre-main sequence stars, which we supplemented with radial velocities from various sources found in the CDS databases. We searched for stars of the Taurus-Auriga region that share the same space velocity, using a modified convergent point method that we tested with extensive Monte Carlo simulations. Results: Among the sample of 217 Taurus-Auriga stars with known proper motions, we identify 94 pre-main sequence stars that are probable members of the same moving group and several additional candidates whose pre-main sequence evolutionary status needs to be confirmed. We derive individual parallaxes for the 67 moving group members with known radial velocities and give tentative parallaxes for other members based on the average spatial velocity of the group. The Hertzsprung-Russell diagram for the moving group members and a discussion of their masses and ages are presented in a companion paper. Accepted by : Astronomy & Astrophysics For preprints, contact Also available from the URL http://arxiv.org/abs/astro-ph/0610506 or by anonymous ftp at ftp:// ................................................... ................................................
Recommended publications
  • A Basic Requirement for Studying the Heavens Is Determining Where In

    A Basic Requirement for Studying the Heavens Is Determining Where In

    Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun­ damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short).
  • Mass Deficits, Stalling Radii, and the Merger Histories of Elliptical Galaxies David Merritt Rochester Institute of Technology

    Mass Deficits, Stalling Radii, and the Merger Histories of Elliptical Galaxies David Merritt Rochester Institute of Technology

    Rochester Institute of Technology RIT Scholar Works Articles 5-22-2006 Mass Deficits, Stalling Radii, and the Merger Histories of Elliptical Galaxies David Merritt Rochester Institute of Technology Follow this and additional works at: http://scholarworks.rit.edu/article Recommended Citation David Merritt 2006 ApJ 648 976 This Article is brought to you for free and open access by RIT Scholar Works. It has been accepted for inclusion in Articles by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. DRAFT VERSION FEBRUARY 5, 2008 Preprint typeset using LATEX style emulateapj v. 10/09/06 MASS DEFICITS, STALLING RADII, AND THE MERGER HISTORIES OF ELLIPTICAL GALAXIES DAVID MERRITT Department of Physics, Rochester Institute of Technology, Rochester, NY 14623 Draft version February 5, 2008 Abstract A binary supermassive black hole leaves an imprint on a galactic nucleus in the form of a “mass deficit,” a decrease in the mass of the nucleus due to ejection of stars by the binary. The magnitude of the mass deficit is in principle related to the galaxy’s merger history, but the relation has never been quantified. Here, high- accuracy N-body simulations are used to calibrate this relation. Mass deficits are shown to be Mde f ≈ 0.5M12, with M12 the total mass of the binary; the coefficient in this relation depends only weakly on M2/M1 or on the galaxy’s pre-existing density profile. Hence, after N mergers, Mde f ≈ 0.5N M• with M• the final (current) black hole mass. When compared with observed mass deficits, this result implies 1 ∼< N ∼< 3, in accord with hierarchical galaxy formation models.
  • Name Glxy Plan Glxy Mltg Glob Glob Open Glob Glxy Glxy Glxy Open

    Name Glxy Plan Glxy Mltg Glob Glob Open Glob Glxy Glxy Glxy Open

    Name 評価 コメント DSO Type Mag. Size Type/ Type/Mag V(HB) RA/Dec (5～1) CenterStar/Mag 5が最高、 V(tip)/#Star 1が最低 NGC 7814 UGC 8 CGCG 456-24 MCG +3-1-20 PGC 218 Glxy 11.6b 6.3x 2.2' 135 SA(s)ab: sp RC3 00 03 15.1 +16 08 45 NGC 40 PK 120+9.1 PNG 120.0+9.8 Plan 10.7p 70.0x60.0" 11.5 3b+3 STE 00 13 00.9 +72 31 19 NGC 55 ESO 293-50 MCG -7-1-13 PGC 1014 Glxy 8.4b 32.3x 5.6' 108 SB(s)m: sp RC3 00 15 08.1 -39 12 53 NGC 70 IC 1539 UGC 174 CGCG 499-108 Arp 113 MCG +5-1-67 PGC 1194 MltG 14.2p 1.9x 1.2' 5 SA(rs)c RC3 00 18 22.6 +30 04 46 NGC 104 Glob 4 50.0' 11.7 14.1 BAA 00 24 05.2 -72 04 51 NGC 121 Glob 1.5' BAA 00 26 41.3 -71 31 24 NGC 136 Cr 4 Open 1.2' 20 13 II 1 p LYN 00 31 31.0 +61 30 36 G 1 Glob 13.7 0.5x 0.5' MAC 00 32 46.3 +39 34 41 NGC 147 UGC 326 CGCG 550-6 MCG +8-2-5 DDO 3 PGC 2004 Glxy 10.5b 13.2x 7.7' 28 E5 pec RC3 00 33 11.6 +48 30 28 NGC 185 UGC 396 CGCG 550-9 MCG +8-2-10 IRAS 362+4803 PGC 2329 Glxy 10.1b 11.9x10.1' 35 E3 pec RC3 00 38 57.7 +48 20 14 M 110 NGC 205 UGC 426 CGCG 535-14 MCG +7-2-14 IRAS PGC 2429 Glxy 8.9b 21.9x10.9' 170 E5 pec RC3 00 40 22.9 +41 41 22 NGC 231 Open 12 1.2x 1.2' 131 15 NGC 00 41 06.5 -73 21 02 M 32 NGC 221 UGC 452 CGCG 535-16 Arp 168 MCG +7-2-15 Arak 12 Glxy 9.0b 8.7x 6.4' 170 cE2 RC3 00 42 41.8 +40 51 56 M 31 NGC 224 UGC 454 CGCG 535-17 MCG +7-2-16 PGC 2557 Glxy 4.4b 192x62' 35 SA(s)b RC3 00 42 44.4 +41 16 NGC 246 PK 118- PNG 118.8- Plan 8.0p 4.1' 11.9 3b STE 00 47 03.6 -11 52 20 NGC 247 UGCA 11 ESO 540-22 MCG -4-3-5 IRAS 446- PGC 2758 Glxy 9.1v 21.4x 6.0' SAB(s)d RC3 00 47 08.7 -20 45 38 NGC 265 Kron 24 Lind
  • Central Massive Objects: the Stellar Nuclei – Black Hole Connection

    Central Massive Objects: the Stellar Nuclei – Black Hole Connection

    Astronomical News Report on the ESO Workshop Central Massive Objects: The Stellar Nuclei – Black Hole Connection held at ESO Garching, Germany, 22–25 June 2010 Nadine Neumayer1 Eric Emsellem1 1 ESO An overview of the ESO workshop on black holes and nuclear star clusters is presented. The meeting reviewed the status of our observational and the- oretical understanding of central mas- sive objects, as well as the search for intermediate mass black holes in globu- lar clusters. There will be no published proceedings, but presentations are available at http://www.eso.org/sci/ meetings/cmo2010/program.html. This workshop brought together a broad international audience in the combined fields of galaxy nuclei, nuclear star clus­ ters and supermassive black holes, to confront state­of­the art observations with cutting­edge models. Around a hundred participants from Europe, North and South America, as well as East Asia and Figure 1. Workshop participants assembled outside made up of several populations of stars. Australia gathered for a three­day meet­ ESO Headquarters in Garching. The existence of very young O and WR ing held at ESO Headquarters in Garching, stars in the central few arcseconds Germany (see Figure 1). The sessions around the black hole is puzzling. The were of very high quality, with many very – Are intermediate mass black holes currently favoured solution to this paradox lively, interesting and fruitful discussions. formed in nuclear clusters/globular of youth is in situ star formation in infalling All talks can be found online on the web clusters? gas clouds. This view is also supported page of the workshop1.
  • Stellar Mass Function in the Field

    Stellar Mass Function in the Field

    Professor David Carter (PI) Liverpool John Moores University UK Dr Habib G. Khosroshahi Liverpool John Moores University UK Mr Mustapha Mouhcine Liverpool John Moores University UK Ms Susan M. Percival Liverpool John Moores University UK Dr Harry C. Ferguson (USA PI) Space Telescope Science Institute USA/MD Dr Paul Goudfrooij Space Telescope Science Institute USA/MD Dr Terry Bridges Queen's University Canada Dr Thomas H. Puzia Dominion Astrophysical Observatory Canada Dr Carlos del Burgo Dublin Institute For Advanced Studies Ireland Dr Bryan Miller Gemini Observatory, Southern Operations Chile Dr Bianca Poggianti INAF - Osservatorio Astronomico di Padova Italy Dr Alfonso Aguerri Instituto de Astrofisica de Canarias Spain Dr Marc Balcells Instituto de Astrofisica de Canarias Spain Mr Derek Hammer Johns Hopkins University USA/MD Dr Reynier F. Peletier Kapteyn Astronomical Institute Netherlands Prof. Edwin Valentijn Kapteyn Astronomical Institute Netherlands Dr Gijs Verdoes Kleijn Kapteyn Astronomical Institute Netherlands Dr Peter Erwin Max-Planck-Insitute for Extraterrestrial Physics Germany Dr Ann Hornschemeier NASA Goddard Space Flight Center USA/MD Dr Yutaka Komiyama National Astronomical Observatory of Japan Japan Dr Masafumi Yagi National Astronomical Observatory of Japan Japan Dr Jennifer Lotz National Optical Astronomy Observatories, AURA USA/AZ National Radio Astronomy Observatory, Dr Neal A. Miller USA/VA and Johns Hopkins University Dr Eric W. Peng Peking University China Dr Dan Batcheldor Rochester Institute of Technology USA/NY Prof. David Merritt Rochester Institute of Technology USA/NY Dr Ronald O. Marzke San Francisco State University USA/CA Dr Alister W. Graham Swinburne University of Technology Australia Dr Helmut Jerjen The Australian National University Australia Dr Avon P.
  • Ngc Catalogue Ngc Catalogue

    Ngc Catalogue Ngc Catalogue

    NGC CATALOGUE NGC CATALOGUE 1 NGC CATALOGUE Object # Common Name Type Constellation Magnitude RA Dec NGC 1 - Galaxy Pegasus 12.9 00:07:16 27:42:32 NGC 2 - Galaxy Pegasus 14.2 00:07:17 27:40:43 NGC 3 - Galaxy Pisces 13.3 00:07:17 08:18:05 NGC 4 - Galaxy Pisces 15.8 00:07:24 08:22:26 NGC 5 - Galaxy Andromeda 13.3 00:07:49 35:21:46 NGC 6 NGC 20 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 7 - Galaxy Sculptor 13.9 00:08:21 -29:54:59 NGC 8 - Double Star Pegasus - 00:08:45 23:50:19 NGC 9 - Galaxy Pegasus 13.5 00:08:54 23:49:04 NGC 10 - Galaxy Sculptor 12.5 00:08:34 -33:51:28 NGC 11 - Galaxy Andromeda 13.7 00:08:42 37:26:53 NGC 12 - Galaxy Pisces 13.1 00:08:45 04:36:44 NGC 13 - Galaxy Andromeda 13.2 00:08:48 33:25:59 NGC 14 - Galaxy Pegasus 12.1 00:08:46 15:48:57 NGC 15 - Galaxy Pegasus 13.8 00:09:02 21:37:30 NGC 16 - Galaxy Pegasus 12.0 00:09:04 27:43:48 NGC 17 NGC 34 Galaxy Cetus 14.4 00:11:07 -12:06:28 NGC 18 - Double Star Pegasus - 00:09:23 27:43:56 NGC 19 - Galaxy Andromeda 13.3 00:10:41 32:58:58 NGC 20 See NGC 6 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 21 NGC 29 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 22 - Galaxy Pegasus 13.6 00:09:48 27:49:58 NGC 23 - Galaxy Pegasus 12.0 00:09:53 25:55:26 NGC 24 - Galaxy Sculptor 11.6 00:09:56 -24:57:52 NGC 25 - Galaxy Phoenix 13.0 00:09:59 -57:01:13 NGC 26 - Galaxy Pegasus 12.9 00:10:26 25:49:56 NGC 27 - Galaxy Andromeda 13.5 00:10:33 28:59:49 NGC 28 - Galaxy Phoenix 13.8 00:10:25 -56:59:20 NGC 29 See NGC 21 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 30 - Double Star Pegasus - 00:10:51 21:58:39
  • Deepsky Observer's Companion

    Deepsky Observer's Companion

    Deepsky Observer’s Companion Auke Slotegraaf Director: Deepsky Observing Section, Astronomical Society of Southern Africa 2002 December Deepsky Observers Companion | 1 1 Deepsky observing for the beginner Some thoughts on 1.1 Just starting out in astronomy? taking up astronomy as a hobby. The following thoughts and suggestions on as- 6. Find other amateurs. “Self-education is tronomy as a hobby have been adapted from an fine as far as it goes, but there’s nothing like article by Alan McRobert (1994) in Sky & Tel- sharing an interest with others.” escope. 7. When it’s time for a telescope, plunge in 1. Ransack your public library. “Astronomy deep. Don’t skimp on quality. “The telescope is a learning hobby ... self-education is some- you want has two essentials. One is a solid, thing you do yourself, with books, using the steady, smoothly working mount. The other is “Two things fill high-quality optics ... You may also want large the mind with ever library.” aperture (size), but don’t forget portability and new and increasing 2. Learn the sky with the naked eye. “As- convenience.” admiration and tronomy is an outdoor nature hobby. Go into awe, the oftener and the night and learn the starry names and pat- 8. Lose your ego. “Astronomy teaches pa- the more steadily terns overhead.” tience and humility - and you’d better be pre- we reflect on them: pared to learn them ... The universe will not 3. Don’t rush to buy a telescope. “To put a the starry heavens bend to your wishes; you must take it on its telescope to rewarding use, you first need to above and the mor- own terms.
  • Accretion Onto a Quintessence Contaminated Rotating Black Hole : Violating the Lower Limit for Eta Over S Arxiv:1911.08304V2 [G

    Accretion Onto a Quintessence Contaminated Rotating Black Hole : Violating the Lower Limit for Eta Over S Arxiv:1911.08304V2 [G

    Accretion onto a Quintessence Contaminated Rotating Black Hole : Violating the Lower Limit for Eta over s Ritabrata Biswas 1 Promila Biswas 3 Parthajit Roy 2∗ 1;3 Department of Mathematics, The University of Burdwan Golapbag Academic Complex, City:Burdwan-713104, Dist: Purba Bardhaman, State: West Bengal, India 1e-mail: [email protected] 3e-mail: [email protected] 2Department of Computer Science, The University of Burdwan City:Burdwan-713104, Dist: Purba Bardhaman, State: West Bengal, India e-mail: [email protected] ∗ Abstract Viscous accretion flow around a rotating supermassive black hole sitting in a quintessence tub is studied in this article. To introduce such a dark energy contaminated black hole's gravitational force, a new pseudo-Newtonian potential is used. This pseudo-Newtonian force can be calculated if we know the distance from the black hole's center, spin of the black hole and equation of state of the quintessence inside which the black hole is considered to lie. This force helps us to avoid complicated nonlinearity of general relativistic field equations. Transonic, viscous, continuous and Keplerian flow is assumed to take place. Fluid speed, sonic speed profile and specific angular momentum to Keplerian angular momentum ratio are found out for different values of spin parameter and arXiv:1911.08304v2 [gr-qc] 2 Mar 2021 quintessence parameter. Density variation is built and tallied with observations. Shear viscosity to entropy density ratio is constructed for our model and a comparison with theoretical lower limit is done. Keywords: Accretion Disc, Viscosity, Quintessence, Supermassive Black Holes, Shear Viscosity to entropy ratio PACS: 97.10.Gz; 51.20.+d; 51.30.+i; 95.36.+x; 97.60.25 1 Introduction Since 1998, despite the propositions of different conceptual models, we were not really able to construct a hundred percent correct theoretical support to the observations of late time cosmic acceleration.
  • Skytools Chart

    Skytools Chart

    36 Ara - Pavo SkyTools 3 / Skyhound.com 2 ζ 6541 NGC 6231 ζ NGC 6124 θ NGC 6322 η η 6496 ζ 1 6388 PK 345-04.1 -4 NGC 6259 NGC 6192 0° 1 ε NGC 6249 ι 1 δ α PK 342-04.1 β IC 4699 μ σ Mu Normae Cluster β2 NGC 6250 NGC 6178 NGC 6204 6352 ω NGC 6200 δ ζ λ θ α IC 4651 NGC 6193 ε ι PK 342-14.1 NGC 6134 6584 6326 NGC 6167 2 Ara γ η 6397 γ1 λ ε1 NGC 6152 α NGC 6208 1 ν μ β 5946 γ ζ NGC 6067 -50° ξ PK 331-05.1 κ 5927 PK 329-02.2 η ζ η NGC 6087 NGC 5999 NGC 5925 Pavo Globular δ 6221 ι1 ξ Collinder 292 α NGC 5822 ν λ 6300 NGC 5823 NGC 6025 π NGC 5749 6744 η PK 325-12.1 γ β β φ1 Pavo δ β NGC 5662 ρ 6362 κ ζ Circinus δ Triangulum Australe ε α Rigel Kentaurus ε 5844 2 -6 α 0 ° β NGC 5617 ζ ζ α Agena 6101 γ γ NGC 5316 ε Apus PK 315-13.1 -7 0° NGC 5281 2 1h h 5 52° x 34° 1 18h 18h00m00.0s -60°00'00" (Skymark) Globular Cl. Dark Neb. Galaxy 8 7 6 5 4 3 2 1 Globule Planetary Open Cl. Nebula 36 Ara - Pavo GALASSIE Sigla Nome Cost. A.R. Dec. Mv. Dim. Tipo Distanza 200/4 80/11,5 20x60 NGC 6221 Ara 16h 52m 47s -59° 12' 59" +10,70 4',6x2',8 Sc 18,0 Mly --- --- --- NGC 6300 Ara 17h 16m 59s -62° 49' 11" +11,00 5',5x3',5 SBb 34,0 Mly --- --- --- NGC 6744 Pav 19h 09m 46s -63° 51' 28" +9,10 17',0x10',7 SABb 21,0 Mly --- --- --- AMMASSI APERTI Sigla Nome Cost.
  • Jack Bennett's Catalogue of Southern Comet-Like Deep-Sky Objects

    Jack Bennett's Catalogue of Southern Comet-Like Deep-Sky Objects

    Jack Bennett’s Catalogue of Southern Comet-like Deep-sky Objects Deep-sky Observing Challenge Compiled by Auke Slotegraaf Director: ASSA Deep-Sky Observing Section. Version 4.2, November 2013 Jack Bennett and his catalogue For two decades, starting in the late 1960’s, the southern sky was patrolled by a dedicated South African comet-hunter named Jack Bennett. He observed from his urban backyard with a 5-inch low-power refractor. Not only did he discover two comets, he also picked up a 9th magnitude supernova in NGC 5236 (M83), becoming the first person ever to visually discover a supernova since the invention of the telescope. Bennett was born on April 6th, 1914 and passed away on May 30th, 1990. A long-standing member of the Astronomical Society of Southern Africa (ASSA), he was elected President in 1969. The Society awarded him the prestigious Gill Medal for services to astronomy in 1970 and in 1986 he received an Honorary Degree of Master of Science from the University of Witwatersrand. In 1989, at the recommendation of Rob McNaught of Siding Springs Observatory, the asteroid VD 4093 was named after him. Bennett was a skilled observer and in the spirit of Charles Messier drew up two lists of southern objects that appeared comet-like in his telescope. His first list (Bennett, 1969) was published four months before he discovered his first comet. The supplementary list (Bennett, 1974) was followed three months later by his second discovery. In his 1969 Presidential Address to the ASSA Bennett said: “As an aid to the recognition of comet-like objects in the Southern sky, and to help observers to eliminate them in comet searches, I have over the past five years compiled a list of 130 such objects visible south of the celestial equator.
  • Galactic Nuclei

    Galactic Nuclei

    Relativity, torque and spin PROFESSOR DAVID MERRITT DAVID PROFESSOR Professor David Merritt explains his interest in astrophysics and the focus of his current research. Describing the improvements made to the computational algorithms, he highlights the importance of taking into account the effects of relativity in these calculations sometimes reveal modes of behaviour that can be inefficient when applied to galactic are strikingly simple yet totally unexpected. nuclei, because motion is dominated by the presence of the SBH. A star or stellar remnant Your current project focuses on the dynamical will complete millions of orbits around evolution of dense clusters of stars and the SBH before coming close enough to stellar remnants around supermassive black another star to be perturbed, but it is those holes (SBHs) at the centre of galaxies. Why is perturbations that are driving the collective this important? evolution. The computer code needs to follow the unperturbed orbit about the SBH with A star like the Sun would be tidally torn apart extremely high precision: otherwise the effects if it came sufficiently close to an SBH. Partly of the small perturbations will be swamped by because of tidal effects, the only objects numerical errors. that we expect to find very near an SBH are ‘compact remnants’: neutron stars and Why is it important to take into account stellar-mass black holes, the dense leftovers the effects of relativity when simulating the from the evolution of massive stars. These evolution of nuclear star clusters? remnants can interact through ‘gravitational encounters’: close passages that exchange One insight that comes from my group’s research energy and gradually change orbits.
  • A Catalogue of Star Clusters Shown on the Franklin-Adams Chart Plates” by P.J

    A Catalogue of Star Clusters Shown on the Franklin-Adams Chart Plates” by P.J

    A Catalogue of Star Clusters shown on the Franklin-Adams Chart Plates” by P.J. Melotte – 1915 Mel. # Alternative(s) Type Const. R.A. Dec. Mag. Size Melotte's comments 1 NGC 104 Globular Tucana 00h24m04s -72°05' 4.00 50' A typical globular cluster. Bright. Well condensed at centre. 2 NGC 188, Collinder 6 Open Cepheus 00h47m28s +85°15' 9.30 17' "A somewhat ill-defined cluster mostly 14th to 16th magnitude stars. 3 NGC 288 Globular Sculptor 00h52m45s -26°35' 8.10 13' Globular cluster, rather loose at centre. 4 NGC 362 Globular Tucana 01h03m14s -70°50' 6.80 14' Globular cluster. Similar to N.G.C. 104 but smaller. Bright. 5 NGC 371 Diffuse Nebula Tucana 01h03m30s -72°03' 13.80 7.5' Globular cluster. Falls in smaller Magellanic cloud, and has every appearance of being a globular cluster. A few stars clustering together. Resembles N.G.C. 582, 645, 659. Difficult to decide whether these should not be 6 NGC 436, Collinder 11 Open Cassiopeia 01h15m58s +58°48' 9.30 5.0' classed II. All the clusters here resemble one another though differing in extent. 7 NGC 457, Collinder 12 Open Cassiopeia 01h19m35s +58°17' 5.10 20' A small cluster in a rich region. 8 M103, NGC 581, Collinder 14 Open Cassiopeia 01h33m23s +60°39' 6.90 5' M. 103. A few stars forming a loose cluster. 9 NGC 654, Collinder 18 Open Cassiopeia 01h44m00s +61°53' 8.20 5' A few stars clustered together in a rich region. 10 NGC 659, Collinder 19 Open Cassiopeia 01h44m24s +60°40' 7.20 5' A few stars clustered together.