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'''Sirius''', also known as '''Alpha Canis Majoris''' or the '''Dog Star''', is the fifth closest [[star]] (counting [[Proxima Centauri]] as a separate star) to our [[Solar System]] at a distance of 8.6 light years, and the second closest [[binary star|binary star system]].  Sirius is also the brightest star in the night sky with an apparent magnitude of -1.46<ref>http://www.atlasoftheuniverse.com/stars.html</ref>.   The star is located in the constellation [[Canis Major]], and is one of the three stars that make up the [[Winter Triangle]].

'''Sirius''', also known as '''Alpha Canis Majoris''' or the '''Dog Star''', is the fifth closest [[star]] (counting [[Proxima Centauri]] as a separate star) to our [[Solar System]] at a distance of 8.6 light years, and the second closest [[binary star|binary star system]].  Sirius is also the brightest star in the night sky with an apparent magnitude of -1.46.<ref>http://www.atlasoftheuniverse.com/stars.html</ref>  The star is located in the constellation [[Canis Major]], and is one of the three stars that make up the [[Winter Triangle]].

==History==

==History==

Sirius A was known throughout human history and was referred to ''Sopdet'' by the ancient Egyptians.  The [[Middle Kingdom]] of Egypt even based its calendar on the first day Sirius would become visible right before sunrise, to indicate the coming annual flooding of the Nile<ref>http://books.google.com/books?id=qUk0GyDJRCoC&pg=PP1&dq=isbn=0306466120&sig=wDa9MW9Qy5f3BIvPvbDLc_LMnJE#PPA500,M1</ref>. The [[ancient Greek]] name for Sirius was Σείριος ''Seirios'', which was derived from σείριος, meaning scorching or destructive. It was seen as a as a herald that forewarned of a hot and dry summer ahead.<ref>http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Canis_Major*.html</ref>   

Sirius A was known throughout human history and was referred to ''Sopdet'' by the ancient Egyptians.  The [[Middle Kingdom]] of Egypt even based its calendar on the first day Sirius would become visible right before sunrise, to indicate the coming annual flooding of the Nile.<ref>http://books.google.com/books?id=qUk0GyDJRCoC&pg=PP1&dq=isbn=0306466120&sig=wDa9MW9Qy5f3BIvPvbDLc_LMnJE#PPA500,M1</ref> The [[ancient Greek]] name for Sirius was Σείριος ''Seirios'', which was derived from σείριος, meaning scorching or destructive. It was seen as a as a herald that forewarned of a hot and dry summer ahead.<ref>http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Canis_Major*.html</ref>   

[[Ptolemy]] was the first to actually map the star in the sky, recorded in the ''Almagest'', or Great Book.  In 1833-34, [[Friedrich Wilhelm Bessel]], concluded that Sirius must have a companion after studying the motions of the star.  The first observable evidence of a companion star didn't occur though until 1862, when '''Alvan Graham Clark''' found Sirius B at the Dearborn Observatory. In 1915, using the [[Mount Wilson Observatory]], '''Walter Sydney Adams''' was the first to discover it as a white dwarf<ref>http://adsabs.harvard.edu/abs/1915PASP...27..236A</ref>. Although the companion was first measured in 1959, it wasn't until 2005, using the [[Hubble Space Telescope]], was an accurate measurement calculated.

[[Ptolemy]] was the first to actually map the star in the sky, recorded in the ''Almagest'', or Great Book.  In 1833-34, [[Friedrich Wilhelm Bessel]], concluded that Sirius must have a companion after studying the motions of the star.  The first observable evidence of a companion star didn't occur though until 1862, when '''Alvan Graham Clark''' found Sirius B at the Dearborn Observatory. In 1915, using the [[Mount Wilson Observatory]], '''Walter Sydney Adams''' was the first to discover it as a white dwarf.<ref>http://adsabs.harvard.edu/abs/1915PASP...27..236A</ref>  Although the companion was first measured in 1959, it wasn't until 2005, using the [[Hubble Space Telescope]], was an accurate measurement calculated.

==The stars==

==The stars==

===Sirius B===

===Sirius B===

Nicknamed “the Pup”, Sirius B is a classified as a white dwarf DA2-5, and is more than 8,200 times as fainter then it's primary (360 times fainter then our Sun). Because the star is a white dwarf, it is extremely dense, holding 97.8% of the Sun's mass but is only 12,000 km in diameter, slightest smaller then the Earth.<ref>http://hubblesite.org/newscenter/archive/releases/2005/36/text/</ref>  Scientists theorize the star was once one of a spectral class B stars much like [[Regulus]] before becoming a red giant and finally a white dwarf.<ref name="SiriusAB">http://solstation.com/stars/sirius2.htm</ref>

Nicknamed “the Pup”, Sirius B is a classified as a white dwarf DA2-5, and is more than 8,200 times as fainter then it's primary (360 times fainter then our Sun). Because the star is a white dwarf, it is extremely dense, holding 97.8% of the Sun's mass but is only 12,000&nbsp;km in diameter, slightest smaller then the Earth.<ref>http://hubblesite.org/newscenter/archive/releases/2005/36/text/</ref>  Scientists theorize the star was once one of a spectral class B stars much like [[Regulus]] before becoming a red giant and finally a white dwarf.<ref name="SiriusAB">http://solstation.com/stars/sirius2.htm</ref>

==Disambiguation==

==Disambiguation==