Post by glactus on Jun 7, 2011 4:02:11 GMT
V 838 Monocerotis
V838 Monocerotis (V838 Mon) is a red variable star in the constellation of Monoceros about 20,000 light years from the Sun, and possibly one of the largest known stars. Apparent magnitude os 6.75.
X-ray of V838 Monocerotis showing central star
The previously unknown star was observed in early 2002 experiencing a major outburst. Originally believed to be a typical nova eruption, it was then realized to be something completely different. The reason for the outburst is still uncertain, but several theories have been put forward, including an eruption related to stellar death processes and a merger of a binary star or planets.
Constellation map
Some details are emerging on the nature of the star that experienced the outburst. Based on an incorrect interpretation of the light echo the eruption generated, the distance of the star was first estimated to be 1,900 to 2,900 light years. Combined with the apparent magnitude measured from pre-eruption photographs, it was thought to be an underluminous F-type dwarf not much unlike our Sun which posed a considerable enigma.
More accurate measurements gave a much larger distance, 20,000 light years (6 kpc). It appears that the star is considerably more massive and luminous than the Sun.
To see movie, click on the URL below. Has sound.
www.youtube.com/watch?v=oi_6GWXJWfI
Looking at V 838
Credits: These are NASA/Hubble images
Text by Wikipedia
Angl0 - Australian observatory
US Naval observatory
Telescope in Avatar: Meade 16" LX 200