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==Polaris in Culture==

==Polaris in Culture==

The traditional name Polaris is one of many known names of the star throughout history.  The [[ancient Greeks]] called the star Φοινίκη or ''Phoenice''.  Another Greek related word was κυνόσουρα or Cynosūra, meaning "the dog's tail", a designation that became popular in reference to the star in 17th and 18th century scientific works.  The [[Bedouin]] of the [[Levant]] referred to the star as الجديّ ''al-jadiyy'', meaning "the billy goat".  [[Arab]] astronomers however named the star ''Al Kaukab al Shamāliyy'', or "the star of the north". For [[Hinduism|Hindu mythology]], Polaris was known first as Grahadhāra, then as Dhruva (a devotee of [[Vishnu]]). <ref>http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Ursa_Minor*.html</ref>

The traditional name Polaris is one of many known names of the star throughout history.  The [[ancient Greeks]] called the star Φοινίκη or ''Phoenice''.  Another Greek related word was κυνόσουρα or Cynosūra, meaning "the dog's tail", a designation that became popular in reference to the star in 17th and 18th century scientific works.  The [[Bedouin]] of the [[Levant]] referred to the star as الجديّ ''al-jadiyy'', meaning "the billy goat".  [[Arab]] astronomers however named the star ''Al Kaukab al Shamāliyy'', or "the star of the north". For [[Hinduism|Hindu mythology]], Polaris was known first as Grahadhāra, then as Dhruva (a devotee of [[Vishnu]]).<ref>http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Ursa_Minor*.html</ref>

==The System==

==The System==

'''Polaris B''' was first discovered by [[William Herschel]] in 1780. As an eighth magnitude star, it can be spotted using a small [[telescope]].  The star is a yellow-white dwarf of spectral type F3 V.  Polaris B orbits its primary with at an average distance of 2400 AU, taking some 42,000 years to complete one orbit.  The mass of the star is estimated to be 1.5 times that of our Sun.<ref>http://arxiv.org/abs/astro-ph/0002406</ref>

'''Polaris B''' was first discovered by [[William Herschel]] in 1780. As an eighth magnitude star, it can be spotted using a small [[telescope]].  The star is a yellow-white dwarf of spectral type F3 V.  Polaris B orbits its primary with at an average distance of 2400 AU, taking some 42,000 years to complete one orbit.  The mass of the star is estimated to be 1.5 times that of our Sun.<ref>http://arxiv.org/abs/astro-ph/0002406</ref>

In 1929 it was discovered that the Polaris system had a third star, now named '''Polaris Ab''', which is very close to the primary star Polaris A.  Polaris Ab is a yellow-white dwarf of spectral class F7 V.  The mass is estimated to be around 1.4 times that of the Sun.<ref name="mass">http://arxiv.org/abs/astro-ph/0609759</ref>  The star orbits the primary at an average distance of 18.5 AU, or about the distance of [[Uranus]] from the Sun.  However the orbit is highly eccentric, running between 27 and 6.7 AU.<ref>http://hubblesite.org/newscenter/archive/releases/2006/02/fastfacts/</ref>

In 1929 it was discovered that the Polaris system had a third star, now named '''Polaris Ab''', which is very close to the primary star Polaris A.  Polaris Ab is a yellow-white dwarf of spectral class F7 V.  The mass is estimated to be around 1.4 times that of the Sun.<ref name="mass"/>  The star orbits the primary at an average distance of 18.5 AU, or about the distance of [[Uranus]] from the Sun.  However the orbit is highly eccentric, running between 27 and 6.7 AU.<ref>http://hubblesite.org/newscenter/archive/releases/2006/02/fastfacts/</ref>

==Polaris as a Pole Star==

==Polaris as a Pole Star==