... 2014 April 22 . The El Gordo Massive Galaxy Cluster . Image Credit: NASA , ESA , J. Jee ( UC Davis ) et al. ... Dubbed "El Gordo", the seven billion light years ( z = 0.87) distant galaxy cluster spans about seven million light years and holds the mass of a million billion Suns. ... That galaxy is actually far in the background and has its image stretched by the gravitational lens action of the massive cluster. Follow APOD on: Facebook , Google Plus , or Twitter . ... About APOD | ...

... 2000 August 30 . The Brown Dwarfs of Orion's Trapezium . ... NICMOS IDT , NASA . ... Explanation: The bright stars above are well known as heart of the Trapezium , an open cluster of stars in the center of the Orion Nebula . ... Although many more brown dwarfs than hot stars have now been found in Orion, their very low masses make them inadequate to compose much of the dark matter expected in galaxies and the Universe . ... About APOD | ... NASA Technical Rep.: ...

. Prague, August 16, 2006 . Present classification : Suggested: . X, XB, XF, XI, XJ, XND, AM (move to cataclysmics), X, X N, XNB (approximately corresponds to XNG, a B star orbiting a compact object), Xlm (low mass), Xhm (high mass), Xmq (microquasars). In this class, advice from experts is especially needed . X-RAY VARIABLES

SN 1999aa - A Third Supernova Discovery . Just 9 weeks after the discovery of SN 1998ey a suspect was found 1" east and 28" north from the centre of NGC 2595 on Feb.11.0166 U.T.. ... Further inspection of 6 images of NGC 2595 taken during Feb. and March 1998 showed no object at the position of the suspect. ... Beijing Astronomical Observatory recorded SN 1999aa on Feb. 11.6 and 12.6 UT, the first obervation being only 14 hours after the discovery. ... Back to Supernova 1999aa in NGC 2595 . ...

... 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. ...

... Sternberg Astronomical Institute , Moscow University . ... Present edition unites two parts of Catalogue of interacting galaxies by B.A.Vorontsov-Velyaminov: the first part (Part 1) containing 355 systems was published in 1959 [1] and the second one (Part 2) with 497 objects - in 1976 [2].Thus two published parts of Catalogue include 852 interacting systems. ... All new of them (1162 by number) were taken from the comments to the galaxies in Morphological catalogue by Vorontsov-Velyaminov et al.[ ...

... The distance scales of the objects are matched both by comparing the first derivatives of the angular velocity determined separately from radial velocities and proper motions and by the statistical-parallax method. ... Good agreement between the inferred 0 and our calculations based on space velocities suggests that the Lindblad relation holds throughout the entire sample volume. ... Brandt and Blitz (1993) published the distances and radial velocities for a total of 206 H II-regions. ... Astron. ...