... March 1, 1999 . Reflection Nebula NGC 1435 . ... Explanation: Reflection nebulae reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s). ... About APOD > . ...

... May 22, 1996 . Star Cluster in the Rosette Nebula . ... Explanation: Embedded in the center of the colorful and photogenic Rosette Nebula is a bright, young open cluster . The bright blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms . ... The Rosette Nebula is thousands of light years distant, but light would take only about 100 years to cross it. ... Tomorrow's picture: The Violent Star Cluster 30 Doradus . ... About APOD | ...

This page is devoted to information on Supernova 1999gi in NGC 3184 . ... Information on the original web pages for many of these images can be found on the Supernova links web page. ... NGC 3184 is a fairly close Mag 10.3 galaxy, only about half as distant as the Virgo cluster. ... Seiichi Yoshida has a 1999gi page . Odd Trondal's 1999gi page . ... CfA image . ... 14.5 . ... Jean Marie Llapasset image . ... vsnet-alert 3805 ] SN 1999gi in NGC 3184 . vsnet-chat 2438 ] Host galaxy of SN1999gi . ...

... E.V. Kazarovets, N.N . Samus , O.V. Durlevich, S.V. Antipin, M.S. Frolov, N.N . Kireeva, E.N. Pastukhova Institute of Astronomy of Russian Academy of Sciences and Sternberg State Astronomical Institute of ... the Moscow State University ================================================================================ The 74th Special Name-list of Variable Stars , A.V. Kazarovets, N.N . Samus , O.V. Durlevich, S.V. Antipin, M.S.,Frolov, ... 3323 Samus, N.N., IBVS, 1997, No. ...

GCVS Variability Types and Distribution Statistics of Designated Variable Stars According to their Types of Variability ======================================================================== I. GCVS Variability Types. ... Amplitudes usually do not exceed 0.1 mag. ... RR Variables of the RR Lyrae type, which are radially-pulsating giant A-F stars having amplitudes from 0.2 to 2 mag in V. Cases of variable light-curve shapes as well as variable periods are known. ... RV Variables of the RV Tauri type. ...

... 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. ...