September 2, 1996
In the time it took you to read this, the Earth moved another thousand miles through space. You are not standing still. You never have been.
Sirius: The Brightest Star in the Night
Birthday · September 2, 1996
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APOD published September 2, 1996. Credit: University of Leicester. A publication-date match, not a photo taken on your date. Independent of NASA.
Sirius is the brightest star in the night sky. Intrinsically, Sirius is over 20 times brighter than our Sun and over twice as massive. As Sirius is 8.7 light years distant, it is not the closest star system -- the Alpha Centauri system holds this distinction. Sirius is called the Dog Star because of its prominence in the constellation of Canis Majoris (Big Dog). In 1862, Sirius was discovered to be a binary star system with a companion star, Sirius B, 10,000 times dimmer than the bright primary, Sirius A. Sirius B was the first white dwarf star discovered, a type of star first understood by Subrahmanyan Chandrasekhar in 1930. While studying Sirius in 1718, Edmond Halley discovered that stars move with respect to each other. The Sirius system is shown above captured in X-ray light.
Image credit: University of Leicester