Variable Star V838 Monocerotis

V838 Monocerotis

Variable star V838 Monocerotis lies near the edge of our Milky Way Galaxy, about 20,000 light-years from the Sun. A sudden outburst was detected in January 2002 and caused scientists to observe the star more closely. The colors are formed by light from the stellar flash echoing across pre-existing dust shells around V838 Mon. This portion of the dust shell is about six light-years in diameter. But because light reflected from the dust follows only a slightly indirect path compared to the direct line-of-sight to the star, the light echoes visible now are only lagging about two years behind the outburst itself. Astronomers expect the expanding echoes to continue to light up the area of V838 Mon for at least the rest of the current decade.