... This gorgeous image of Orion shows off the constellation's young stars and cosmic clouds of hydrogen gas and dust. Made with a film camera tracking the stars on November 11, the exposure lasted some 40 minutes. M13: The Great Globular Cluster in Hercules . ... The Inner Coma of Comet Holmes . ... What's happening to Comet Holmes? ... That high energy fundamental particles are barreling through the universe has been known for about a century. NGC 6888: The Crescent Nebula . ... November . ...

Еще в разделе: (Показать все результаты (>121589) - www.astronet.ru/ )

Today's APOD | ... Editor's choices for the most educational Astronomy Pictures of the Day about open clusters: . APOD: 2006 January 9 - M45: The Pleiades Star Cluster . ... The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. ... Two types of star clusters are visible in our Milky Way Galaxy : open clusters and globular clusters . ... Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. ... Index | ...

Еще в разделе: (Показать все результаты (>5960) - www.sai.msu.su/ )

• APOD: 2000 May 23 - M4: The Closest Known Globular Cluster
• APOD: January 28, 1997 - Open Cluster M50
• APOD: 2003 December 15 - Open Star Clusters M35 and NGC 2158

.

Еще в разделе: (Показать все результаты (>51438) - www.eso.org/ )

• Wide-field view of the bright star clusters Messier 47 and Messier 46
• The location of the bright star cluster NGC 3532 in the constellation of Carina
• The bright star cluster Messier 7 in the constellation of Scorpius

... Tonight's Sky . ... The Magazine . ... Observing . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Bright planets meet at dusk . ... Astronomy magazine subscribers can read the full article for free. ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter....

Еще в разделе: (Показать все результаты (>6488) - www.astronomy.com/ )

• The Queen's clusters | Astronomy.com
• globular clusters | Astronomy.com

... STScI-PRC00-25 A DYING STAR IN GLOBULAR CLUSTER M15 The globular cluster Messier 15 is shown in this color image obtained with the NASA Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2). ... Known as Kuestner 648, this was the first planetary nebula to be identified in a globular cluster. ... At the present time, the most massive stars remaining in M15 have about 80 percent of the mass of our Sun, a fact that makes the existence of a planetary nebula like K 648 something of a mystery. ...

Еще в разделе: (Показать все результаты (>7167) - www.arcetri.astro.it/ )

• APOD: 2000 August 4 - M15: Dense Globular Star Cluster
• Two VLT Unit Telescopes in Action (ESO Press Release 07/99)

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

Еще в разделе: (Показать все результаты (>448) - www.atmob.org/ )

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Image credit:ESO/J.Emerson/VISTA. ... However others are less pessimistic and it has even been claimed that the mysterious ?Wow! signal? received in 1977 originated from the direction M55.б  Sadly, this still unexplained pulse of radio energy originated from a location rather to the northwest of M55 so I doubt if the source was this cluster (if indeed the signal was genuinely of extraterrestrial origin). ... Mysterious Wow! ...

Еще в разделе: (Показать все результаты (>2781) - www.armaghplanet.com/ )

• NGC4666: Secrets of a Starburst Galaxy | Astronotes
• Omega Centauri: globular cluster of 300,000 stars | Astronotes
• Stargazing in June | Astronotes

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

Еще в разделе: (Показать все результаты (>183) - zebu.uoregon.edu/ )

• Astro-2 and the UIT Experiment
• The Galaxy Gallery Page IX: Clusters of Galaxies
• Low Surface Brightness Galaxy Gallery

... Radio source identifications . The Web-server of the Special Astrophysical Observatory supports the mirror version of the Clusters of Galaxies database . At present only the data about radio sources in ACO clusters of galaxies are reasonably complete, while only restricted optical information is in our database. Later on, we also intend to include X-ray data and data about brightest cluster galaxies (BCG). ... ACO: radio optic ( for example, A0690 and " optic "), . ...

Еще в разделе: (Показать все результаты (>869) - www.sao.ru/ )

• A 20 cm VLA survey of Abell clusters of galaxies
• A 1400-MHz Survey of 1478 Abell Clusters of Galaxies
• A VLA Survey of Rich Clusters of Galaxies I.

... From the data taken during Cycle 1, surface brightness profiles have been obtained for 13 globular clusters in M31 (Fusi Pecci et al. 1993), leading also to the detection of a central cusp in a candidate post-core-collapse cluster (Bendinelli et al. ... Surface brightness profiles obtained with VISTA. ... PSF 512 512, data matrix smaller and smaller (256 256, 128 128, 64 64), sky = 0, RMG (Fig. 3b): the derived profiles remain unaffected a part from the reduction in radial extension. ...

Еще в разделе: (Показать все результаты (>12398) - www.stsci.edu/ )

• Globular Cluster NGC 5986
• Simulation of a Distant Cluster of Normal Galaxies
• Combined IRAC2 vs HST Color-Magnitude Diagrams of Bulge Globular Clusters.

... This paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...

Еще в разделе: (Показать все результаты (>1710) - hea-www.harvard.edu/ )

• The AstroStat Slog Globular Clusters
• Doug Burke: Publications List
• The AstroStat Slog clusters

... Bad Astronomy . ... Bitesize Astronomy . ... The next step up are true clusters, called open clusters . Open clusters (sometimes misleadingly called "galactic clusters") are groups of stars ranging in size from a few dozen stars up to tens of thousands. ... The youngest is about 1 or 2 million years old, while the oldest is about 6 or 7 billion years, making it just older than our own solar system. ... So by looking at the stars in the cluster we can tell pretty well how old they are. ...

Еще в разделе: (Показать все результаты (>206) - www.badastronomy.com/ )

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...

Еще в разделе: (Показать все результаты (>241) - mavr.sao.ru/ )

• important_en
• articles_flera_en
• articles_alex_01

... Our Milky Way galaxy is host to a number of companions. These companions are gravitationally bound to the Milky Way and are stellar systems in their own right. They include a population of about 150 globular clusters (GCs) and some 30 dwarf satellite galaxies (DSGs). ... These DSGs are more extended and diffuse compared to GCs. In fact the larger satellites of the Milky Way (and other galaxies, for that matter) host their own small systems of GCs. ...

Еще в разделе: (Показать все результаты (>735) - www.astrosociety.org/ )

• ASP: Big Clusters, Tiny Galaxies
• ASP: Star Science in the Autumn Sky
• ASP: An Ancient Universe - Pleiades

A Canadian and American team of Astronomers have used the 305-m wide Arecibo radio dish, the world's largest and most sensitive radio telescope, to uncover a dozen new super-fast-spinning pulsars. The team directed their search for these rare and exotic stars by pointing the Arecibo radio telescope towards massive star clusters, called Globular Clusters, orbiting our Milky Way galaxy. ... One of the most exotic residents in the Globular cluster system are the millisecond pulsars. ...

Еще в разделе: (Показать все результаты (>1311) - www.naic.edu/ )

• The Pleiades

You Can Make Stellar Images Brighter . Articles | ... A few months ago I wrote an article titled "You Can’t Make Them Brighter". So why am I now writing that you can make them brighter. ... The image of a focused star is actually a small disk called the Airy disk, named after the 19 th century scientist Sir George Airy. ... For a given aperture, a smaller Airy disk means that the light is focused to a smaller disk and is therefore brighter. ... www.astronomy.net . About Astronomy Net | ...

Еще в разделе: (Показать все результаты (>1001) - www.astronomy.net/ )

• The Astronomy Shop - Books - by Astronomy Net
• Finding Himalia, The Fifth Brightest Moon Of Jupiter - an Astronomy Net Article
• You Can't Make Stellar Images Brighter - an Astronomy Net Article

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

Еще в разделе: (Показать все результаты (>222) - ocl.sai.msu.ru/ )

• SAI OCL Catalog Publications
• SAI OCL Catalog Structure

... BLUE STRAGGLER STARS are unusually hot and bright stars found in the cores of ancient star clusters known as globulars. ... BACKGROUND (from wikipedia): Blue straggler stars are stars in open or globular clusters that are hotter and bluer than other cluster stars having the same luminosity. ... There is evidence in favor of this view, notably that blue straggler stars appear to be much more common in dense regions of clusters, especially in the cores of globular clusters. ...

Еще в разделе: (Показать все результаты (>399) - www.mso.anu.edu.au/ )

• GSAOI Super Star Clusters Science Page
• GSAOI Globular Cluster Science Page
• IAU Commission #37 (Star Clusters and Associations)

Searching for Ultra Compact Binaries in Globular Clusters What Are Ultra Compact Binaries? ... An ultra compact binary is a binary that consists two white dwarf To source the FITS files that contained the UV images, the sky coordinates stars and has an orbital period shorter than ~70min (A binary and the details on brightness for each star in each globular cluster we were consists of two stars orbiting around their centre of mass, it enables investigating, we used the XMM online archive. ...

Еще в разделе: (Показать все результаты (>1980) - star.arm.ac.uk/ )

• Hale-Bopp Finding Chart 3
• Armagh Observatory
• Terry Mosely's Bulletins

Feb 28 2016 Cepheus - The King IC 455 5mm TV VF,VS,OVAL, NND ,R=F Galaxy S0 Nov 16 2012 18 IC 469 5mm TV Galaxy SAB(rs)ab: VF,VS,OVAL,VEXT, NND ,AV2,R=F Nov 16 2012 18 IC 1396 19mmW 25mmPL Open Cluster II3mn **STARS,BRIGHT, NICE DUST LANES,R=G DECENT NIGHT - MEGASTAR CONTROL Sep 07 2005 8 May 22 2004 8 NGC 40 7.5mmW 7.5mmW H58-4 MB,R,R=G Planetary Neb 3b+3 F,VS,R,VSMBM,*12SP Nov 11 2009 12 Oct 06 ... 13 Jul 24 2006 8" Aug 21 2004 8" PB,CS,R=F CLEAR SKIES - H.H. LITE. ...

Еще в разделе: (Показать все результаты (>464) - www.wro.org/ )

• Table of Asterisms