... 2001 December 10 . Globular Cluster M15 . ... Explanation: Stars, like bees, swarm around the center of bright globular cluster M15. This ball of over 100,000 stars is a relic from the early years of our Galaxy , and continues to orbit the Milky Way's center . ... The above image , taken in ultraviolet light with the WIYN Telescope , spans about 120 light years and shows the gradual increase in stars toward the cluster's center. ... About APOD | ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. December 18, 1999 . Irregular Galaxy Sextans A . ... Their newly formed, bright, blue star clusters found along beautiful, symmetric spiral arms are guaranteed to attract attention. But small irregular galaxies form stars too , like this lovely, gumdrop-shaped galaxy, Sextans A . ... About APOD > . ...

Supernova 2009js in NGC 918 . This page is devoted to information on Supernova 2009js in NGC 918 . Basic information on this SN, including the last reported brightness, on this Supernova can be found on the main page . Information on the original web pages for many of these images can be found on the updates and links web pages. Discovered independently by Lick Observatory Supernova Search (USA) and Koichi Itagaki (Japan). ... 2009/10/11.44 . 17.2 . ... Joseph Brimacombe . ...

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 . ...

... At present, he is a Leading researcher at the Department of Non-Stationary Stars and Stellar Spectroscopy, heading the group of the General Catalogue of Variable Stars, and a Leading researcher at the Department of Variable Stars and Galactic Astronomy of the Sternberg Astronomical Institute, heading the group of Variable Stars. ... P.P. Parenago, B.V. Kukarkin, P.N. Kholopov leaded the team of variable star catalogue compilers at Astronomical Council/INASAN and at Sternberg Institute through years....

... Here is a brief outline of the current theory of the events in the early history of the solar system: . A cloud of interstellar gas and/or dust (the "solar nebula") is disturbed and collapses under its own gravity. ... The gas cools off enough for the metal, rock and (far enough from the forming star) ice to condense out into tiny particles. (i.e. some of the gas turns back into dust). ... Once the larger of these particles get big enough to have a nontrivial gravity, their growth accelerates. ...