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The Most Massive Star Cluster in the Local Group
This is a repository copy of A 'super' star cluster grown old: the most massive star cluster in the Local Group. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/144713/ Version: Published Version Article: Ma, J., De Grijs, R., Yang, Y. et al. (5 more authors) (2006) A 'super' star cluster grown old: the most massive star cluster in the Local Group. Monthly Notices of the Royal Astronomical Society , 368 (3). pp. 1443-1450. ISSN 0035-8711 https://doi.org/10.1111/j.1365-2966.2006.10231.x This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2006 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Mon. Not. R. Astron. Soc. 368, 1443–1450 (2006) doi:10.1111/j.1365-2966.2006.10231.x A ‘super’ star cluster grown old: the most massive star cluster in the Local Group J. -
Nightwatch Club Events Calendar President's Message
Henry Wadsworth Longfellow Henry Wadsworth Thewithfilled skyby day. is stars, invisible Volume 32 Number 06 nightwatch June 2012 President's Message Club Events Calendar Busy days right now, both in the heavens and here on Earth. June 8 - General Meeting – Speaker Robert Stephens - I've heard lots of good reports of people successfully viewing the “A Journey Through the Asteroid Belt” eclipse on May 20. My own eclipse trip to Page, Arizona, was a June 16 - Star Party - White Mountain smashing success. The lunar eclipse early in the morning on June 22 - Star Party - Cottonwood Springs - joint with June 4 was clouded out, at least here in Claremont. By the time Palm Springs Braille Institute you read this, the transit of Venus across the face of the sun on June 5 will already have happened. I hope you got a chance to July 2 - School Star Party - Colony High School, Ontario see it—it won't happen again until 2117. July 5 - Board Meeting, 6:15 We also have some great club events coming up. Our speaker July 13 - General Meeting for the June 8 general meeting is Robert Stephens July 21 – Star Party – Cottonwood Springs (http://planetarysciences.org/stephens.html), who will give us “A July 24 - Ontario Library Main Branch - Dark to 9pm Journey Through the Asteroid Belt”. On June 16 we'll have a star July 25 – Star Party – Orange County Braille Institute, party at White Mountain. My annual curse has struck again—I'll Anaheim be in New York looking at fossils instead of on White Mountain looking at stars, but I hope you all have fun without me. -
Eagle Nebula Star Formation Region
Eagle Nebula Star Formation Region AST 303: Chapter 17 1 The Formation of Stars (2) • A cloud of gas and dust must collapse if stars are to be formed. • The self-gravity of the cloud will tend to cause it to collapse. • Radiation pressure from nearby hot stars may do the same. • The passage of a shock wave from a nearby supernova blast or some other source (such as galactic shock waves) may do the same. – Note: The “sonic boom” of a jet plane is an example of a shock wave. • When two clouds collide, they may cause each other to collapse. AST 303: Chapter 17 2 Trifid Nebula AST 303: Chapter 17 3 Trifid Nebula Stellar Nursery Revealed AST 303: Chapter 17 4 Young Starburst Cluster Emerges from Cloud AST 303: Chapter 17 5 The Formation of Stars (3) • The gas in the collapsing cloud probably becomes turbulent. • This would tend to fragment the collapsing gas, producing condensations that would be the nuclei of new stars. • There is abundant evidence that shows that the stars in a cluster are all about the same age. For a young cluster, many stars have not yet reached the main sequence: ! Isochron Luminosity "Temperature AST 303: Chapter 17 6 The Formation of Stars (4) • The evolutionary paths of young stars on the H-R diagram look like this. Note the T Tauri stars, long thought to be young stars. • Theory says that these stars use convection as the main method of transporting energy to their surfaces. ! T Tauri Stars Luminosity "Temperature AST 303: Chapter 17 7 The Search for Stellar Precursors • Astronomers have long been fascinated by very dark, dense regions seen outlined against bright gas, called globules. -
The ISO/LWS Spectrum of the Egg Nebula, AFGL 2688 ? ; P
Astron. Astrophys. 315, L265–L268 (1996) ASTRONOMY AND ASTROPHYSICS The ISO/LWS spectrum of the Egg nebula, AFGL 2688 ? ; P. Cox 1 ;8 ,E.Gonz´alez-Alfonso2,M.J.Barlow3,X.-W.Liu3,T.Lim4, B.M. Swinyard5, J. Cernicharo6 2,A.Omont7, E. Caux8,C.Gry4;10, M.J. Griffin9,J.-P.Baluteau10,P.E.Clegg9,S.Sidher4,D.P´equignot11, Nguyen-Q-Rieu12, K.J. King5, P.A.R. Ade9,W.A.Towlson3,R.J.Emery5,I.Furniss3,M.Joubert13, C.J. Skinner14,M.Cohen15,C.Armand4,M.Burgdorf4, D. Eward4, A. Di Giorgio4, S. Molinari4, D. Texier4,N.Trams4,S.J.Unger5,W.M.Glencross3, D. Lorenzetti16, B. Nisini16, R. Orfei16, P. Saraceno16, and G. Serra8 1 Institut d’Astrophysique Spatiale, Bat.^ 120, Universite´ de Paris XI, F-91405 Orsay, France 2 Observatorio Astronomico Nacional. Apartado 1143. E-28800 Alcala de Henares, Spain 3 Dept. of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK 4 The LWS Instrument-Dedicated-Team, ISO Science Operations Centre, P.O. Box 50727, E-28080 Madrid, Spain 5 Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK 6 Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid, Spain 7 Institut d’Astrophysique de Paris, C.N.R.S., 98b bd. Arago, F-75014 Paris, France 8 Centre d’Etude Spatiale des Rayonnements, CESR/CNRS-UPS, BP 4346, F-31029 Toulouse Cedex, France 9 Dept. of Physics, Queen Mary and Westfield College Mile End Road, London E1 4NS, UK 10 Laboratoire d’Astronomie Spatiale, CNRS, BP 8, F-13376 Marseille Cedex 12, France 11 Observatoire de Paris, Section d’Astrophysique, F-92190 Paris, France 12 Observatoire de Paris, 61 avenue de l’Observatoire, F-75014 Paris, France 13 CNES, 2 place Maurice Quentin, F-75001 Paris, France 14 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 15 Radio Astronomy Laboratory, 601 Cambell Hall, University of California, Berkeley, CA 94720, USA 16 CNR-Instituto di Fisica dello Spazio Interplanetario, Casella Postale 27 I-00044 Frascati, Italy Received 15 July 1996 / Accepted 13 September 1996 Abstract. -
The Ellipticities of Globular Clusters in the Andromeda Galaxy
ASTRONOMY & ASTROPHYSICS MAY I 1996, PAGE 447 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 116, 447-461 (1996) The ellipticities of globular clusters in the Andromeda galaxy A. Staneva1, N. Spassova2 and V. Golev1 1 Department of Astronomy, Faculty of Physics, St. Kliment Okhridski University of Sofia, 5 James Bourchier street, BG-1126 Sofia, Bulgaria 2 Institute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko chauss´ee, BG-1784 Sofia, Bulgaria Received March 15; accepted October 4, 1995 Abstract. — The projected ellipticities and orientations of 173 globular clusters in the Andromeda galaxy have been determined by using isodensity contours and 2D Gaussian fitting techniques. A number of B plates taken with the 2 m Ritchey-Chretien-coud´e reflector of the Bulgarian National Astronomical Observatory were digitized and processed for each cluster. The derived ellipticities and orientations are presented in the form of a catalogue?. The projected ellipticities of M 31 GCs lie between 0.03 0.24 with mean valueε ¯=0.086 0.038. It may be concluded that the most globular clusters in the Andromeda galaxy÷ are quite spherical. The derived± orientations do not show a preference with respect to the center of M 31. Some correlations of the ellipticity with other clusters parameters are discussed. The ellipticities determined in this work are compared with those in other Local Group galaxies. Key words: globular clusters: general — galaxies: individual: M 31 — galaxies: star clusters — catalogs 1. Introduction Bergh & Morbey (1984), and Kontizas et al. (1989), have shown that the globulars in LMC are markedly more ellip- Representing the oldest of all stellar populations, the glo- tical than those in our Galaxy. -
Drilling Through the M31 Halo Near Mayall-II/G1
Drilling through the M31 Halo near Mayall-II/G1 Michael Gregg University of California, Davis Michael West Lowell Observatory Brian Lemaux University of California, Davis Andreas Küpper Quantco, Inc. Origin of the brightest Globulars Clusters Mayall-II/G1 in M31 Omega Cen in Milky Way •G1 has mass of ~107 M⊙ and σ = 25 km/s •High ellipticity, ~0.2, 50% rotationally supported •Metallicity spread, ~0.45 dex •Evidence for massive blackhole in the core, ~104 M⊙ •=> Former dwarf galaxy nucleus, now Ultra-Compact Dwarf? Origin of the brightest Globulars Clusters ...and connection to galaxy halo formation… HST image of nucleated Typical UCD (or bright globular) dwarf elliptical in in the same galaxy cluster: the Fornax galaxy cluster: possibly a tidally stripped nucleus nucleus + envelope of stars Origin of the brightest Globulars Clusters... Fornax Galaxy Cluster ...and connection to galaxy halo formation… image credit: M. Hilker •Evolved tidal streams are too faint (∼> 30 mag/sq.′′) to detect with standard imaging (Ibata et al. 2001; Ferguson et al. 2002; etc., etc., etc.) •Need resolved star spectroscopy to identify tidal debris; characteristics can perhaps can yield insight into the precursor of G1… G1 in Context Chemin et al. (2009) • We view G1 projected against the outer disk of M31, 2.6˚ (34 kpc) distant from the bulge. • The M31 disk has v < −500 km s-1 at G1 (Chemin et al. 2009). • G1 systemic v = −332 ± 3 km s-1 (Galleti et al. 2006), separation of ∼ 170 km s-1, 5-6 times the velocity dispersion of G1 or the M31 cold disk. -
Stars and Their Spectra: an Introduction to the Spectral Sequence Second Edition James B
Cambridge University Press 978-0-521-89954-3 - Stars and Their Spectra: An Introduction to the Spectral Sequence Second Edition James B. Kaler Index More information Star index Stars are arranged by the Latin genitive of their constellation of residence, with other star names interspersed alphabetically. Within a constellation, Bayer Greek letters are given first, followed by Roman letters, Flamsteed numbers, variable stars arranged in traditional order (see Section 1.11), and then other names that take on genitive form. Stellar spectra are indicated by an asterisk. The best-known proper names have priority over their Greek-letter names. Spectra of the Sun and of nebulae are included as well. Abell 21 nucleus, see a Aurigae, see Capella Abell 78 nucleus, 327* ε Aurigae, 178, 186 Achernar, 9, 243, 264, 274 z Aurigae, 177, 186 Acrux, see Alpha Crucis Z Aurigae, 186, 269* Adhara, see Epsilon Canis Majoris AB Aurigae, 255 Albireo, 26 Alcor, 26, 177, 241, 243, 272* Barnard’s Star, 129–130, 131 Aldebaran, 9, 27, 80*, 163, 165 Betelgeuse, 2, 9, 16, 18, 20, 73, 74*, 79, Algol, 20, 26, 176–177, 271*, 333, 366 80*, 88, 104–105, 106*, 110*, 113, Altair, 9, 236, 241, 250 115, 118, 122, 187, 216, 264 a Andromedae, 273, 273* image of, 114 b Andromedae, 164 BDþ284211, 285* g Andromedae, 26 Bl 253* u Andromedae A, 218* a Boo¨tis, see Arcturus u Andromedae B, 109* g Boo¨tis, 243 Z Andromedae, 337 Z Boo¨tis, 185 Antares, 10, 73, 104–105, 113, 115, 118, l Boo¨tis, 254, 280, 314 122, 174* s Boo¨tis, 218* 53 Aquarii A, 195 53 Aquarii B, 195 T Camelopardalis, -
Mayall II= G1 in M31: Giant Globular Cluster Or Core of a Dwarf Elliptical
Mayall II ≡ G1 in M31: Giant Globular Cluster or Core of a Dwarf Elliptical Galaxy? 1,2 G. Meylan3 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, U.S.A., email: [email protected], and European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei M¨unchen, Germany. A. Sarajedini University of Florida, Astronomy Department, Gainesville, FL 32611-2055, U.S.A. email: [email protected]fl.edu P. Jablonka DAEC-URA 8631, Observatoire de Paris-Meudon, Place Jules Janssen, F-92195 Meudon, France. email: [email protected] S. G. Djorgovski Palomar Observatory, MS 105–24, Caltech, Pasadena, CA 91125, U.S.A. email: [email protected] T. Bridges Anglo-Australian Observatory, PO Box 296, Epping, NSW 2121, Australia. email: [email protected] R. M. Rich UCLA, Physics & Astronomy Department, Math-Sciences 8979, Los Angeles, CA 90095-1562, U.S.A. email: [email protected] 1 Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associate with proposal IDs 5907 and 5464. arXiv:astro-ph/0105013v1 1 May 2001 2 Based in part on observations obtained at the W.M. Keck Observatory, which is operated jointly by the California Institute of Technology and the University of California. 3 Affiliated with the Astrophysics Division of the European Space Agency, ESTEC, Noordwijk, The Netherlands. ABSTRACT Mayall II ≡ G1 is one of the brightest globular clusters belonging to M31, the Andromeda galaxy. -
The Egg Nebula 15 April 2019
Image: the Egg Nebula 15 April 2019 Eventually the star stops shedding material and the core remnant heats up, exciting the expelled gas so that it glows brightly and becomes a planetary nebula. The dark band, sweeping beams, and criss- crossing arcs in this image can reveal a lot about the complex environment of a dying star. The central band is a cocoon of dust hiding the star from view. Beams of light emanate from the obscured star, and it is thought that they are due to starlight escaping from the ring-shaped holes in the dusty cocoon that surrounds the star. The holes are possibly carved by a high-speed stream of matter, although the cause of these jets are unknown. The Credit: Raghvendra Sahai and John Trauger (JPL), the spoke-like features are shadows cast by blobs of WFPC2 science team, and NASA/ESA material within the region of the holes in the cocoon. Numerous bright arcs intersect the beams: these The Egg Nebula is a preplanetary nebula, created are shells of matter ejected by the star. The arcs by a dying star in the process of becoming a are like tree rings, and can tell us something about planetary nebula. Planetary nebulas have nothing the object's age as they reveal that the rate of mass to do with planets – the name arose when 18th ejection has varied between 100 and 500 years century astronomers spotted them in their throughout its 10 000 year history. The gas is telescopes and thought they looked like planets. expanding at a rate of 20 km/s and matter has been Instead, they are the remnants of material expelled detected out to a radius of 0.6 light years, providing by Sun-like stars in the later stages of their lives. -
New Type of Black Hole Detected in Massive Collision That Sent Gravitational Waves with a 'Bang'
New type of black hole detected in massive collision that sent gravitational waves with a 'bang' By Ashley Strickland, CNN Updated 1200 GMT (2000 HKT) September 2, 2020 <img alt="Galaxy NGC 4485 collided with its larger galactic neighbor NGC 4490 millions of years ago, leading to the creation of new stars seen in the right side of the image." class="media__image" src="//cdn.cnn.com/cnnnext/dam/assets/190516104725-ngc-4485-nasa-super-169.jpg"> Photos: Wonders of the universe Galaxy NGC 4485 collided with its larger galactic neighbor NGC 4490 millions of years ago, leading to the creation of new stars seen in the right side of the image. Hide Caption 98 of 195 <img alt="Astronomers developed a mosaic of the distant universe, called the Hubble Legacy Field, that documents 16 years of observations from the Hubble Space Telescope. The image contains 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang. " class="media__image" src="//cdn.cnn.com/cnnnext/dam/assets/190502151952-0502-wonders-of-the-universe-super-169.jpg"> Photos: Wonders of the universe Astronomers developed a mosaic of the distant universe, called the Hubble Legacy Field, that documents 16 years of observations from the Hubble Space Telescope. The image contains 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang. Hide Caption 99 of 195 <img alt="A ground-based telescope&amp;#39;s view of the Large Magellanic Cloud, a neighboring galaxy of our Milky Way. -
The 2011 Observers Challenge List
TMSP OBSERVER'S CHALLENGE 2011 By Kreig McBride and Tom Masterson All observations must be made at TMSP and 25 out of 30 objects must be viewed to earn a unique TMSP Observer's Award lapel pin. You must create a record of your observations which include date, time, instruments used and a brief description and/or sketch of the object. Your records will be returned to you. Size or ID Number V Magnitude Object Type Constellation RA Dec Description Separation The Sun! View 2 days noting changes. H-alpha, white 1 Sol -28m ½ degree Star Cancer 08h 39' +27d 07' light or projection is OK North Galactic Astronomical Catch this one before it sets. Next to the double star 31 2 N/A N/A Coma Berenices 12h 51' +27d 07' Pole Reference point Comae Berenices Omicron-2 a wide 4.9m, 9m double lies close by as does 3 U Cygni 5.9 – 12.1m N/A Carbon Star Cygnus 19.6h +47d 54' 6” diameter, 12.6m Planetary nebula NGC6884 4 M22 5.1m 7.8' Globular Cluster Sagittarius 18h 36.4' -23d 54' Rich, large and bright 5 NGC 6629 11.3m 15” Planetary Nebula Sagittarius 18h 25.7' -23d 12' Stellar at low powers. Central Star is 12.8m 6 Barnard 86 N/A 5' Dark Nebula Sagittarius 18h 03' -27d 53' “Ink Spot” Imbedded in spectacular star field Faint 1' glow surrounding 9.5m star w/a faint companion 7 NGC 6589-90 N/A 5' x 3' Reflection Nebula Sagittarius 18h 16.9'' -19d 47' 25” to its SW A 3.2m, B Reddish/Orange primary, B white, C is 10m companion 8 ETA Sagittarii 3.6m, C 10m, AB pair 3.6” Quadruple Star Sagittarius 18h 17.6' -36d 46' 93” distant at PA303d and D is 13m star 33” -
Lick Observatory Records: Photographs UA.036.Ser.07
http://oac.cdlib.org/findaid/ark:/13030/c81z4932 Online items available Lick Observatory Records: Photographs UA.036.Ser.07 Kate Dundon, Alix Norton, Maureen Carey, Christine Turk, Alex Moore University of California, Santa Cruz 2016 1156 High Street Santa Cruz 95064 [email protected] URL: http://guides.library.ucsc.edu/speccoll Lick Observatory Records: UA.036.Ser.07 1 Photographs UA.036.Ser.07 Contributing Institution: University of California, Santa Cruz Title: Lick Observatory Records: Photographs Creator: Lick Observatory Identifier/Call Number: UA.036.Ser.07 Physical Description: 101.62 Linear Feet127 boxes Date (inclusive): circa 1870-2002 Language of Material: English . https://n2t.net/ark:/38305/f19c6wg4 Conditions Governing Access Collection is open for research. Conditions Governing Use Property rights for this collection reside with the University of California. Literary rights, including copyright, are retained by the creators and their heirs. The publication or use of any work protected by copyright beyond that allowed by fair use for research or educational purposes requires written permission from the copyright owner. Responsibility for obtaining permissions, and for any use rests exclusively with the user. Preferred Citation Lick Observatory Records: Photographs. UA36 Ser.7. Special Collections and Archives, University Library, University of California, Santa Cruz. Alternative Format Available Images from this collection are available through UCSC Library Digital Collections. Historical note These photographs were produced or collected by Lick observatory staff and faculty, as well as UCSC Library personnel. Many of the early photographs of the major instruments and Observatory buildings were taken by Henry E. Matthews, who served as secretary to the Lick Trust during the planning and construction of the Observatory.