Reflection Nebula NGC2261 - Hubble's Variable Nebula - AR 06h 38m 14s DEC +08° 45' 09"
Date/Place2016-12-29 at Elijah Observatory
ScopeGSO RC10 Truss
IntegrationLRGB composition.
L:49 x 690 sec. at bin 1
RGB: (6,6,6) x 600 sec. at bin 2
Frame acquisition by Astroscheduler.
CommentThis nebula is famous for its continuous variations in shape and brightness (hence the name); these variability were discovered on a series of photographic plates produced some years ago in the middle of the twentieth century by Carl Otto Lampland. These variations do not coincide with the cycle of variability of its inner star, R Monocerotis, while the nebula becomes periodically obscured in the same part; this led Lampland to believe that there was a rotating dark nebula that always obscured it at the same point when it passed over our line of sight. In 1959, George Herbig noted that the central star was actually a very bright and tiny triangular nebula, which in turn contained a newly formed star; this was the first of a series of similar objects discovered later. It is thought that this type of structure may have existed even four billion years ago around our Sun during the formation of the planets.The central star of the nebula is a reality a double star, formed by two components, the brightest of which is about 10 times larger than the Sun; however their light is not observable in the band of visible light, but only in the infrared, due to the dense nebulosity. Probably the system is composed of two T Tauri stars, formed about 300,000 years ago. The variability of the nebula is thought to be due to the fact that the filaments of gas are expelled from the protoplanetary disk in a double cone shape, which follow the lines of the magnetic field of the star, thus causing observable variations.(Text from Wikipedia)