Date: 1999 - 2000
Why is Sirius(the Dog star/Canis Major) the brightest star
in our galaxy?
Sirius is the brightest star in our sky, not necessarily in the galaxy. The
apparent brightness of a star is a function of its absolute brightness and the
distance to the star. (This assumes that you are comparing the same
frequencies of light. Not all stars put off the same frequency of light.)
You might want to read about apparent and absolute brightness. It will help
you to understand better. It is also interesting to explore why it is called
the dog star.... and how it relates to the "dog days of summer."
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Update: June 2012