Thursday, December 4, 2008

List of stellar records:part 3



To the lower left is Sirius B.
Photo: Nasa, Hubble Telescope

Optical brightest star: Sirius A

Sirius
Sirius is the brightest star in the sky (except the Sun of course).
It is a double system of a hot blue-white main sequence star (Sirius A) and a white dwarf (Sirius B).
Actually Sirius B was once the bigger of the two, before it pushed away its hull.

Constellation: Canis Major
Age: 300 million years
Distance: 8.601 light-years
Radial velocity: -9.1 km/sec
Space between Sirius A and B: 19.7 AE
Orbit period of Sirius A and B: 50.09 years

Sirius A
Spectral class: A1
Visual magnitude: -1.43
Luminosity: 22.61 * Sun
Mass: 2.35 * Sun
Diameter: 2.03 * Sun

Sirius B
Spectral class: DA2
Visual magnitude: 8.44
Luminosity: 0.00255 * Sun
Mass: 0.98 * Sun
Diameter: 0.007 * Sun
Density: 92 000 * Sun

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