... 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. ...