Monday, June 14, 2010

Interesting factoids you didn’t know about Sirius, ‘The Dog Star’

Sirius_A_and_B_artwork Sirius, the brightest star in the night sky, also known as “The Dog Star,” is in the ancient constellation of Canis Major, literally meaning “large dog.” Below are a few interesting facts that you may or may not have known about The Dog Star.

Sirius gets its name from the ancient Greek work Seirios, literally meaning “scorcher.” It also goes by other names as well, such as Alpha Canis Majoris, Canicula, and Aschere.

  • What you see as a single star is actually a binary star system comprised of a white main sequence star, Sirius A and its white dwarf companion, Sirius B.
  • The phrase “dog days of summer” comes from an ancient belief that the Dog Star was somehow responsible for the hot weather because, next to the Sun, it was the largest star in the heavens. The term “Dog Days” was first used by ancient Greeks.
  • Ancient Egyptians based their calendars on heliacal rising of Sirius, which is when it first becomes visible above the eastern horizon just before sunrise after a period of not being visible.
  • Sirius B is so dim that it cannot be perceived by the naked eye, and was not observed until January 31, 1862 by Alvan Graham Clark. Clark was later honored with the Lalande prize by the French Academy for this discovery.
  • Sirius A is approximately 2.02 to 2.14 times the mass of our Sun and about 1.68 to 1.71 its diameter.
  • Sirius B, also known as “the Pup” is 8200 times dimmer than its companion, Sirius A, but is actually the hotter of the two.


  1. Great post! I always wanted a telescope growing up, but never got one :(

  2. I want to express my appreciation to this writer for resucing from this type of setting. Thanks


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