mardi 23 septembre 2008

Canis Minor 2

Canis Minor is Orion's second hunting dog, trailing behind in the skies. Much smaller than its mate, its only point of interest is in its principal star, Procyon.
The name means "Before the Dog", referring to the fact that this star rises just before Sirius (alpha CMa). At 11.44 light years away, Procyon is nearly as close to us as Sirius (8.65 ly).
There are only nine Bayer stars, which range from 0.38 to nearly sixth magnitude.

Double stars in Canis Minor
Procyon A and Procyon B form an extremely difficult binary. In fact the companion, which is a white dwarf with a diameter of only twice that of Earth's, was first seen only in 1896. Since then its orbit, which is nearly circular, has been calculated to be 40.65 years.
In 2000 the values are: 0.4, 10.3; PA 150º, separation 4.6".

Variable stars in Canis Minor
Beta CMi is a gamma Cas type variable, fluctuating from 2.84 to 2.92.

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