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Line 14: − + − The name ''Aldebaran'' itself is from (الدبران ''al-dabarān''), which translates as "the follower". It is believed this is in reference to the star "following" the [[Pleiades]]. The name was once given to the nearby [[open cluster]] of the [[Hyades]], which Aldebaran was likely seen as part of due to its apparent proximity (although in reality, the star is not related to the stars of the Hyades).+ − − + − The Aldebaran system is located some 65.1 light years away. The two individual stars of the binary system orbit each other with a mean distance of 607 AU. It was once thought that a nearby binary pair made up of a K5 and M2 dwarf were also part of the system, however they are in reality an optical binary (stars that visually appear to be part of a system but are not actually gravitationally bound to it), located much further away from our [[Solar System]]. The primary, Aldebaran A, is thought to possibly have a gas giant in close orbit.+ − − + − The primary star, '''Aldebaran A''', is a [[red giant|orange-red giant]] of spectral type K5 III. Before becoming a [[helium]] fusing giant star, it is believed that Aldebaran A was a class A spectral dwarf. It is estimated to have between one and 2.5 the mass of the [[Sun]], with a diameter is around 43-44 times as great, enough to extend half way to the orbit of [[Mercury]].<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1993ApJ...413..339H&data_type=PDF_HIGH&type=PRINTER&ext=.pdf</ref> The surface temperature is a relatively cool 4010 K (the Sun in contrast has a surface temperature of 5780 K). Like all red giants, the star is highly luminous, with a total luminousity 425 times as great as the Sun when accounting for the [[infrared]].<ref>http://stars.astro.illinois.edu/sow/aldebaran.html</ref> The star's [[metallicity]] is estimated between 47 and 100 percent of our Sun's, based on the abundance of [[iron]] found.<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1992A%26AS...95..273C</ref>+ − − − − Line 51:
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Fix Template
| declination =α Tau A: +16<sup>o</sup> 30′ 33.49″<br/>α Tau B: +16<sup>o</sup> 30′ 22″
| declination =α Tau A: +16<sup>o</sup> 30′ 33.49″<br/>α Tau B: +16<sup>o</sup> 30′ 22″
| distance =65.1 ly
| distance =65.1 ly
| constellation =[[Taurus]]
| constellation =Taurus
| type =[[Binary star]]
| type =Binary star
| dimensions =
| dimensions =
| magnitude =α Tau A: Apparent Mag: 0.75-0.95 Absolute Mag: −0.63<br/>α Tau B: Apparent Mag: +13.6 absolute Mag: 11.98
| magnitude =α Tau A: Apparent Mag: 0.75-0.95 Absolute Mag: −0.63<br/>α Tau B: Apparent Mag: +13.6 absolute Mag: 11.98
| redshift =
| redshift =
| parallax =50.09 ± 0.95 mas
| parallax =50.09 ± 0.95 mas
}}
}}
'''Aldebaran''', also called '''Alpha Tauri''', is the brightest star of the constellation [[Taurus]] with an apparent magnitude of 0.87. The star is actually a [[binary star|binary pair]] consisting of a [[red giant]] and [[red dwarf]], although only the giant Aldebaran A is visible to the unaided eye.
'''Aldebaran''', also called '''Alpha Tauri''', is the brightest star of the constellation [[Taurus]] with an apparent magnitude of 0.87. The star is actually a [[binary star|binary pair]] consisting of a [[red giant]] and [[red dwarf]], although only the giant Aldebaran A is visible to the unaided eye.
==Aldebaran in Culture and History==
==Aldebaran in Culture and History==
The name ''Aldebaran'' itself is from (الدبران ''al-dabarān''), which translates as "the follower". It is believed this is in reference to the star "following" the [[Pleiades]]. The name was once given to the nearby [[open cluster]] of the [[Hyades]], which Aldebaran was likely seen as part of due to its apparent proximity, despite the star being technically unrelated to the stars of the Hyades.
[[Ptolemy]] referred to the star as Λαμπαδίας, meaning "torch bearer"; it was also known in [[ancient Greece]] as Λαμπαύρας.
[[Ptolemy]] referred to the star as Λαμπαδίας, meaning "torch bearer", it was also known in [[ancient Greece]] as Λαμπαύρας.
In [[Hindu]] astronomy, the star was known as ''Rohinī'', meaning a red deer, likely due to the reddish-orange gow of the star. For the [[Chinese]], it was called (畢宿五 ''Bìxiùwŭ''), meaning "the Fifth Star of the Net".<ref>http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Taurus*.html</ref>
In [[Hindu]] astronomy, the star was known as ''Rohinī'', meaning a red deer, likely due to the reddish-orange gow of the star. For the [[Chinese]], it was called (畢宿五 ''Bìxiùwŭ''), meaning "the Fifth Star of the Net".<ref>http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Taurus*.html</ref>
==Star System==
==Star System==
The Aldebaran system is located some 65.1 light years away. The two individual stars of the binary system orbit each other with a mean distance of 607 AU. It was once thought that a nearby binary pair made up of a K5 and M2 dwarf were also part of the system, but in reality they are an optical binary (stars that visually appear to be part of a system but are not actually gravitationally bound to it), located much further away from our [[Solar System]]. The primary, Aldebaran A, is thought to possibly have a gas giant in close orbit.
Because Aldebaran is located near the [[ecliptic]], it is regularly occulted by the [[Moon]] near the time of the autumn equinox, with the next occurrence happening in 2015. It is this occultation that originally allowed for the accurate measurement of Aldebaran's size.<ref>http://adsabs.harvard.edu/full/1979AJ.....84..872W</ref>
Because Aldebaran is located near the [[ecliptic]], it is regularly occulted by the [[Moon]] near the time of the autumn equinox, with the next occurrence happening in 2015. It is this occultation that originally allowed for the accurate measurement of Aldebaran's size. <ref>http://adsabs.harvard.edu/full/1979AJ.....84..872W</ref>
===Aldebaran A===
===Aldebaran A===
The primary star, '''Aldebaran A''', is a [[red giant|orange-red giant]] of spectral type K5 III. Before becoming a [[helium]] fusing giant star, it is believed that Aldebaran A was a class A spectral dwarf. It is estimated to have between 1 and 2.5 the mass of the [[Sun]], with a diameter is around 43-44 times as great, enough to extend half way to the orbit of [[Mercury]].<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1993ApJ...413..339H&data_type=PDF_HIGH&type=PRINTER&ext=.pdf</ref> The surface temperature is a relatively cool 4010 K (the Sun in contrast has a surface temperature of 5780 K). Like all red giants, the star is highly luminous, with a total luminousity 425 times as great as the Sun, when accounting for the [[infrared]].<ref>http://stars.astro.illinois.edu/sow/aldebaran.html</ref> The star's [[metallicity]] is estimated between 47 and 100 percent of our Sun's, based on the abundance of [[iron]] found.<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1992A%26AS...95..273C</ref>
The star is a [[variable star]], classified specifically as an irregular variable type ''LB''. The variation of the star is small enough to be undetectable by human eyes, with an apparent magnitude change of only some 0.2 percent.<ref>http://www.konkoly.hu/cgi-bin/IBVS?4480</ref>
The star is a [[variable star]], classified specifically as an irregular variable type ''LB''. The variation of the star though is so small, it isn't detectable by human eyes, with only an apparent magnitude change of some 0.2 percent.<ref>http://www.konkoly.hu/cgi-bin/IBVS?4480</ref>
===Aldebaran B===
===Aldebaran B===
The secondary star, '''Aldebaran B''', is a [[red dwarf]] star of spectral type M2 V. If alone, the star would be far too dim to see from [[Earth]] in the night sky, as it has an apparent magnitude of only 13.6. The small star has around 15 percent of the Sun's mass and 3 percent of its diameter. As a dim red dwarf, the star only has .0014 of a percent of the Sun's luminosity.
The secondary star, '''Aldebaran B''', is a [[red dwarf]] star of spectral type M2 V. If alone, the star would be far too dim to see from [[Earth]] in the night sky, as it has an apparent magnitude of only 13.6. The small star has around 15 percent of the Sun's mass and 3 percent of its diameter. As a dim red dwarf, the star only has .0014 of a percent of the Sun's luminosity.
===Planetary System===
===Planetary System===
In 1997, it was announced by astronomers that a [[planet]] was discovered in orbit around Aldebaran A via measurements of oscillations in the star's long term radial velocity.<ref>http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998MNRAS.293..469H&db_key=AST&high=3769fd414921247</ref> The planet though has yet to be independently confirmed, with some astronomers being skeptical, believing that the variation in radical velocity is due to the long term oscillation of the star itself.
In 1997, it was announced by astronomers that a [[planet]] was discovered in orbit around Aldebaran A via measurements of oscillations in the star's long term radial velocity.<ref>http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998MNRAS.293..469H&db_key=AST&high=3769fd414921247</ref> The planet though has yet to be independently confirmed, with some astronomers being skeptical, believing that the variation in radical velocity is due to the long term oscillation of the star itself.
[[Category:Double Stars]]
[[Category:Double Stars]]
[[Category: Astronomy]]
[[Category:Astronomy]]