... 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) . ...

. I measured my limiting magnitude on this picture at about Mag 18.9. I also did some photometry near for the SN positon, and I found a star liked object at about Mag 17.6. I think this object is 1999br. This image is deconvoluted, but I measured the magnitude pre-deconvulution. Kereszty Zsolt . Hungary, Miskolc . Back to Bright Supernovae . David Bishop Last modified: Thu Apr 15 11:44:03 EDT 1999

... 2000 December 15 . IC443's Neutron Star . ... Explanation: Using x-ray data from the orbiting Chandra Observatory along with radio data from the Very Large Array , a team of researchers has discovered evidence for a new example of one of the most bizarre objects known to modern astrophysics -- a neutron star . ... The core collapsed when the star, located a reassuring 5,000 light-years away in the constellation Gemini , exploded long ago. How long ago? ... About APOD | ... NASA Technical Rep.: ...

... Prague , 2006 . ... The draft classification (version August 9, 2006 ) for new GCVS versions . Along with the "+" sign (coexistence of two types), it is suggested to introduce the "|" sign (meaning "or") - for classification options for the same object, e.g. EC|Ell, EC|RR. Pulsating variables . ... DCEP , DCEPS , CEP ( B ) DCep , DCep 0, DCep 1, DCepB 01, DCepB 12 . ... Eruptive variables . ... PN, WD, WR Remove from the classification, indicate through the spectral type or Remarks . ...

... 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.[ ...

... 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. ...

... 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. ...