V838 Monocerotis
V838 Monocerotis ( V838 Mon short ) is one Luminous Red Nova in the constellation Unicorn ( Monoceros ). He is about 6.1 kiloparsecs (20,000 light years) from Earth and has an apparent magnitude of 15.74 mag.
The designation V838 Monocerotis means " 838 variable star of Monoceros ( the Unicorn ) ".
Outbreak
The outbreak was discovered on January 6, 2002 by NJ Brown. By comparison with archive images, it was found that he must have taken place at January 1, 2002 after the recording of J. operating. The first outbreak was comparable relatively unspectacular and with the behavior of a star of type nova.
The second outbreak was discovered on 2 February 2002 in Innsbruck and independently a few hours later in the Czech Republic and Poland. His light echo was discovered on February 17 at the U.S. Naval Observatory and led by its rapid expansion at the beginning of misjudgment that the object is only about 700 parsecs away.
This second outbreak and the very unusual behavior subsequently led to the observation by the Hubble Space Telescope. The pictures went around the world and later led to the erroneous assumption that there had been a discovery by the Hubble.
The star was the outbreak in a few days ten thousand times brighter than before and thus brighter than all other stars of the Milky Way.
Today it is known that the star is located at a distance of about ( 6100 ± 800 ) parsec. These two independent measurement methods were used.
Hubble was able to since February 9, 2002 create about 120 shots. The previous latest being on 28 September 2009 and was taken with the long-wave filter F814 in the beginning of the infrared light spectrum. Astronomers expect that reflections of this outbreak will be visible until 2010.
After the supernova 1987A this is the second event in which in a spectacular way, the light echo produced was absorbed by material ( which was located in the immediate vicinity of a star ). But light echoes are and have long been in the professional world intensively used tool for the investigation of variable stars and were very often observed.
Through radio observations of the CO lines of the origin of the charge of the light echo material could be found. It is a the V838 Mon - group surrounding molecular cloud. For V838 Mon - group nor include not only the namesake of at least three early stars with spectral classes B3 to B6 and B3 companion of V838 Monocerotis. Since the molecular cloud has not yet been resolved despite the intense ultraviolet radiation of the early stars, the maximum age of the cloud and thus of V838 Mon is estimated to be less than 25 million years.
V838 Mon lost in this outbreak as opposed to novae or supernovae hardly matter at high speed, but ballooned enormously and turned into a cool supergiant with a diameter of about 1.56 billion kilometers.
From 2004 to 2006, the observations showed signs of a blue companion star. This seems to have reached about December 2005, the ever-expanding shell. Finally, the envelope has reached 2006 Dimensions in October, in which the companion was completely swallowed.