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The traditional name of Rigel stems from its location in the [[Orion]] constellation.  The name is derived from the [[Arabic]] ''Riǧl Ǧawza al-Yusra'', meaning "Left foot of the Central One", as the star is seen as the "left foot" of [[constellation]].  Another Arabic name for the star is ''riǧl al-ǧabbār'' or "the foot of the great one".  In Western culture, the star traditionally represents the left foot of the mythical hunter Orion of Greek mythology. Usually the The foot is mistakenly associated with Beta Eridani, which is really one of the stars that represents his footstool. The [[Chinese]] referred to the star as 参宿七 or ''Shēnxiù Qī'', meaning "The Seventh of the Three Stars".  

The traditional name of Rigel stems from its location in the [[Orion]] constellation.  The name is derived from the [[Arabic]] ''Riǧl Ǧawza al-Yusra'', meaning "Left foot of the Central One", as the star is seen as the "left foot" of [[constellation]].  Another Arabic name for the star is ''riǧl al-ǧabbār'' or "the foot of the great one".  In Western culture, the star traditionally represents the left foot of the mythical hunter Orion of Greek mythology. Usually the The foot is mistakenly associated with Beta Eridani, which is really one of the stars that represents his footstool. The [[Chinese]] referred to the star as 参宿七 or ''Shēnxiù Qī'', meaning "The Seventh of the Three Stars".  

Rigel is also one of the most important stars used in [[celestial navigation]] throughout the history of oceanic sailing.  This is due to both the star's relative brightness and its equatorial location, making it visible in most [[ocean]] [[latitude|latitudes]].

Rigel is also one of the most important stars used in [[celestial navigation]] throughout the history of oceanic sailing.  This is due to both the star's relative brightness and its equatorial location, making it visible in most [[ocean]] [[latitude]]s.

==Star System==

==Star System==

===Rigel A===

===Rigel A===

[[Image:Rigel sun comparision.png|thumb|right|250px|Artist rendering of Rigel compared in size to our Sun.]]

[[Image:Rigel sun comparision.png|thumb|right|250px|Artist rendering of Rigel compared in size to our Sun.]]

Rigel A is classified as a blue-white [[supergiant]] of spectral class B8 Iab.  The star contains some 17 times the mass of our [[Sun]].  While the radius of Rigel is estimated to be 74 times that of the Sun, so large, that if Rigel was at the center of our solar system, it would extend to the orbit of [[Mercury]].<ref name="illinois">http://www.astro.illinois.edu/~jkaler/sow/rigel.html</ref>  The star has 40,000 times the Sun's visual luminosity.<ref name="illinois">http://www.astro.illinois.edu/~jkaler/sow/rigel.html</ref>  Much of Rigel's radiation however, is in the [[ultraviolet]], when this is accounted for, the star's total luminosity is 150,000 times the Sun's.<ref name="star">http://www.nasa.gov/worldbook/star_worldbook.html</ref>

Rigel A is classified as a blue-white [[supergiant]] of spectral class B8 Iab.  The star contains some 17 times the mass of our [[Sun]].  While the radius of Rigel is estimated to be 74 times that of the Sun, so large, that if Rigel was at the center of our solar system, it would extend to the orbit of [[Mercury]].<ref name="illinois"/>  The star has 40,000 times the Sun's visual luminosity.<ref name="illinois"/>  Much of Rigel's radiation however, is in the [[ultraviolet]], when this is accounted for, the star's total luminosity is 150,000 times the Sun's.<ref name="star">http://www.nasa.gov/worldbook/star_worldbook.html</ref>

Like other stars of its category, Rigel burns through its core [[hydrogen]] very quickly.  Rigel will soon burn through its hydrogen fuel in the core, if it hasn't already done so, and will eventually expand to become a red [[supergiant]].  Given Rigel's mass, it will most likely end its life in a [[supernova]] explosion.  If Rigel does go supernova, it will appear as bright as a quarter [[moon]].

Like other stars of its category, Rigel burns through its core [[hydrogen]] very quickly.  Rigel will soon burn through its hydrogen fuel in the core, if it hasn't already done so, and will eventually expand to become a red [[supergiant]].  Given Rigel's mass, it will most likely end its life in a [[supernova]] explosion.  If Rigel does go supernova, it will appear as bright as a quarter [[moon]].

===Rigel B===

===Rigel B===

Rigel B is a class B9 V star of magnitude 6.7, making it just slightly too dim to be seen with the unaided eye, even if the star was alone.<ref name="peter">Jedicke, Peter; Levy, David H. (1992). "Regal Rigel". The New Cosmos. Waukesha: Kalmbach Books. pp. 48–53.</ref>  Because Rigel A is some 500 times as bright, Rigel B is obscured by its companion, making observations challenging. Rigel B itself is some 2500 AU from its primary (or some 60 times the distance Pluto is from the Sun) taking 25,000 years to orbit.<ref name="illinois">http://www.astro.illinois.edu/~jkaler/sow/rigel.html</ref>

Rigel B is a class B9 V star of magnitude 6.7, making it just slightly too dim to be seen with the unaided eye, even if the star was alone.<ref name="peter">Jedicke, Peter; Levy, David H. (1992). "Regal Rigel". The New Cosmos. Waukesha: Kalmbach Books. pp. 48–53.</ref>  Because Rigel A is some 500 times as bright, Rigel B is obscured by its companion, making observations challenging. Rigel B itself is some 2500 AU from its primary (or some 60 times the distance Pluto is from the Sun) taking 25,000 years to orbit.<ref name="illinois"/>

Some astronomers have claimed that Rigel B itself is actually a double, and if so would more accurately be called Rigel BC.  However the idea of Rigel B being a double star in itself is still highly controversial, with proponents unable to repeatedly duplicate their initial results.<ref name="peter">Jedicke, Peter; Levy, David H. (1992). "Regal Rigel". The New Cosmos. Waukesha: Kalmbach Books. pp. 48–53.</ref>

Some astronomers have claimed that Rigel B itself is actually a double, and if so would more accurately be called Rigel BC.  However the idea of Rigel B being a double star in itself is still highly controversial, with proponents unable to repeatedly duplicate their initial results.<ref name="peter"/>

There is also a 15th magnitude class K star, referred to as Rigel D, believed to be associated with the other stars of the Rigel system.  It is estimated to be some 11,500 AU from Rigel A and its companion, and if part of the system, would take some 250,000 years to orbit the primary.<ref name="illinois">http://www.astro.illinois.edu/~jkaler/sow/rigel.html</ref>

There is also a 15th magnitude class K star, referred to as Rigel D, believed to be associated with the other stars of the Rigel system.  It is estimated to be some 11,500 AU from Rigel A and its companion, and if part of the system, would take some 250,000 years to orbit the primary.<ref name="illinois"/>

[[Category:Astronomy]]

[[Category:Astronomy]]