VV Cephei

Starbox begin
name=VV Cephei Starbox astrometry
absmag_v= -9 Starbox character
class=M2 Iab starbox detail
radius = 1600-1900
mass = 25-40 or 100
luminosity = 275,000-575,000(bolometric)
temperature = 3300-3650starbox observe
epoch=J2000
ra = 21h 56m 39.14s
dec = +63° 37′ 32″
constell=Cepheus

VV Cephei is an eclipsing binary star system located in the constellation Cepheus, approximately 3,000 light years from Earth.A red supergiant fills the system's Roche lobe when closest to its companion blue star, the latter appearing to be on the main sequence. Matter flows from the red supergiant onto the blue companion.

VV Cephei A

VV Cephei A, the supergiant, is one of the largest stars known, and believed the third largest star in this galaxy (after the hypergiant WOH G64).It is of spectral type M2 and is approximately 1,600–1,900 times the Sun's diameter.If placed in our solar system, the binary system would extend past the orbit of Jupiter and approach that of Saturn. VV Cephei is 275,000-575,000 times more luminous than the Sun. As is true for many red supergiants, a stellar wind flows off the system at a velocity of approximately 25 kilometers per second. [W. H. Bauer, P. D. Bennett, & A. Brown 2007 Astrophysical Journal Supplement Series 171, 249-259.] VV Cephei A's mass estimated from its orbital motion is about 100 solar masses, but its luminosity suggests a mass 25-40 solar masses. Consequently, the actual mass is unknown.

See also

*List of largest stars
*List of most luminous stars
*VY Canis Majoris

References

* http://www.hposoft.com/Astro/PEP/VVCephei.html
* http://www.astro.uiuc.edu/~kaler/sow/vvcep.html

External links

* [http://www.space.com/scienceastronomy/aas_largest_stars_050110.html Space.Com]
* [http://www.universetoday.com/am/publish/three_largest_stars.html Universe Today]
* [http://video.google.com/videoplay?docid=-3974466981713172831&sourceid=Himself Google Video (Scale of VV Cephei compared to Earth Video)]