... We sometimes use the word "nebula" to refer to galaxies, various types of star clusters and various kinds of interstellar dust/gas clouds. ... Early in this century, there was a great debate as to the nature of the nebulae like this one which at that time could not be resolved into individual stars. ... A typical galaxy is 100,000 light-years in diameter. ... M 42 shown) Reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars. ... M 1 shown) . ...

... 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. ...

... Observations . Objects . ... Canis Major . ... Canis Minor . ... Leo . ... Leo Minor . ... Ursa Major . ... Ursa Minor . ... Herschel 2500 . ... Herschel 400 (I) . ... Globular Clusters . ... AL Globular Club . ... AL Planetary Club . ...

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! ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Governance overview . Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Parkes radio telescope . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... RV Tau Variables in Globular Clusters - clues on their nature? ... This is a report of the detailed elemental abundances of RV Tau variables that reside in globular clusters, and how they compare with RV Tau variables in the field. ...

... 22.09.2000 . ... Credit: B.J. Mochejska , J. Kaluzny ( CAMK ), 1m Swope Telescope Explanation: The fifty-fifth entry in Charles Messier's catalog, M55 is a large and lovely globular cluster of around 100,000 stars. ... Astronomers who make detailed studies of globular cluster stars can accurately measure the cluster ages and distances. ... Publications with keywords: star cluster - cluster - globular cluster - m55 . Publications with words: star cluster - cluster - globular cluster - m55 . ...

... 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. ...

... Commission 37: Star Clusters and Associations . Home Page . Commission 37 of the International Astronomical Union deals with all aspects of Globular Cluster, Open Cluster, and Stellar Associations research. With Commission 33 it forms Division VII of the IAU. Commission Structure . ... IAU Home Page . Open Clusters Database (maintained by J.-C. Mermilliod ) . Catalogue of Milky Way Globular Cluster Parameters (maintained by W. E. Harris ) . ...

... Radio source identifications . The Web-server of the Astronomical Institute of the St.-Petersburg University opens the experimental service on assignment of clusters data. 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 "), . ...

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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. ...

... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... SUBJECT: 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... which will be held in Beijing, P.R. China, from August 25-29, 2014, hosted by Chinese Academy of Sciences . ... China), . ... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. ...

We present Spitzer Space Telescope IRAC and MIPS observations of the Galactic globular cluster M15 (NGC 7078), one of the most metal-poor clusters, with a [Fe/H]=-2.4. Our Spitzer images reveal a population of dusty red giants near the cluster center, a previously detected planetary nebula designated K648, and a possible detection of the intracluster medium arising from mass-loss episodes from the evolved stellar population. ...

... 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. ...

ABSOLUTE PROPER MOTIONS OF 331 OPEN CLUSTERS . ... The proper motions of stars in the fields of 331 open clusters were taken from Four-Million Star Catalog (4M-catalog) of positions and proper motions (Volchkov et al. ... The absolute proper motions for 21 young open clusters have been derived by comparison of precise relative proper motions of individual stars and their corresponding absolute proper motions. ... Sign of proper motions in RA . ... 0.0001 arcsec/yr . ... rms error in RA proper motion . ...

... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

... 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 ...

... Tonight's Sky . ... The Magazine . News . Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... Galactocentric distance dependences of the physical parameters of globular clusters. ... The straight line in (a) is the rms regression. The large circles in (b) show mean masses within narrow R intervals, and the solid lines show the rms regression fits for thick-disk and old-halo (left) and young-halo and corona (right) clusters. The dashed lines in (c) and (d) are upper and lower envelopes drawn by eye. discussion in the text | privious figure | next figure . ...

... Club By-laws . ... Other Club Activities . ... Public Nights . ... Dr. James Green, NASA, Director Planetary Science will be our esteemed speaker on Tuesday, April 12, 2016 at 7:30 PM in Peyton Hall on the Princeton University campus. ... Our astronomers setup telescopes for public use at Communiversity in Princeton, Super Science Saturday at the NJ State Museum in Trenton and at various public events around Mercer County. ... Amateur Astronomers Association of Princeton, Inc., ...