Aldebaran

Aldebaran

Aldebaran (lower right) in the Bull's head is close to the Sun every year around May 31. Credit: NASA SOHO C3
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Taurus
Right ascension	04h 35m 55.2s
Declination	+16° 30' 33"
Apparent magnitude (V)	+0.85 / +13.50
Characteristics
Spectral type	K5III / M2V
U-B color index	1.90 / ?
B-V color index	1.54 / ?
Variable type	Suspected / ?
Astrometry
Radial velocity (Rv)	+53.8 km/s
Proper motion (μ)	RA: 62.78 mas/yr Dec.: −189.36 mas/yr
Parallax (π)	50.09 ± 0.95 mas
Distance	65 ± 1 ly (20 ± 0.4 pc)
Absolute magnitude (MV)	−0.63 / 11.98
Details
Aldebaran A
Mass	2.5 M☉
Radius	44.2[1] R☉
Temperature	4,100 K
Metallicity	70% Sun
Aldebaran B
Mass	0.15 M☉
Radius	0.04 R☉
Luminosity	0.00014 L☉
Temperature	3,050 K
Other designations
87 Tauri, Alpha Tauri, BD +16°629, Cor Tauri, Gl 171.1, GJ 9159, HD 29139, HIP 21421 HR 1457, Paliliya, Parilicium, SAO 94027
Database references
SIMBAD	data

Aldebaran (α Tau, α Tauri, Alpha Tauri) is the brightest star in the constellation Taurus and one of the brightest stars in the nighttime sky. The name Aldebaran is derived from Arabic signifying "the follower", as it appears to follow the Pleiades, or Seven Sisters in the sky^[2]. Because of its location in the head of Taurus, it has historically been called the Bull's Eye. Aldebaran has the appearance of being the brightest member of the more scattered Hyades cluster, which is the closest star cluster to Earth. However, it is merely located in the line of sight between the Earth and the Hyades, and is actually an independent star. NASA's Pioneer 10 spacecraft, which flew by Jupiter in 1973, is currently travelling in the direction and will reach it in about two million years..

In 1997, a possible substellar companion was reported, with a mass at least 11 times that of Jupiter with an orbital period of around 2 years; however, this has not been confirmed.

Physical properties

Size comparison between Aldebaran and the Sun

Aldebaran is a K5III star, which means it is orangish, large, and has moved off the main sequence after exhausting the hydrogen fuel in its core. It has a minor companion (a dim M2 dwarf orbiting at several hundred AU). Now primarily fusing helium, the main star has expanded to a diameter of 44.2 times the diameter of the Sun,^[1][3] approximately 61 million kilometres (see 10 gigametres for similar sizes). The Hipparcos satellite has measured it as 65.1 light-years (20.0 pc) away, and it shines with 150 times the Sun's luminosity. With an apparent magnitude of 0.87, it is the 13th brightest star. It is slightly variable, of the irregular variable type, by about 0.2 magnitude.

Visibility

Aldebaran is one of the easiest stars to find in the night sky, partly due to its brightness and partly due to its spatial relation to one of the more noticeable asterisms in the sky. If one follows the three stars of Orion's belt from left to right (in the Northern Hemisphere) or right to left (in the Southern), the first bright star found by continuing that line is Aldebaran.

This star is close enough to the ecliptic to be occulted by the moon. Such occultations occur when the moon's ascending node is near the autumnal equinox, as will be the case around 2015.

Possible planetary system

In 1993, radial velocity measurements of Aldebaran A, Arcturus and Pollux showed that Aldebaran A exhibited a long-period radial velocity oscillation, which could be interpreted as a substellar companion with a minimum mass 11.4 times that of Jupiter in a 643-day orbit at a separation of 2.0 AU (300 Gm) in a mildly eccentric orbit.^[4] However, all three stars surveyed showed similar oscillations yielding similar companion masses, and the authors concluded that the variation was likely to be intrinsic to the star rather than due to the gravitational effect of a companion. On the other hand, it should be noted that the companion to the star Pollux postulated in the 1993 paper has since been confirmed (see Pollux b).^[5]

Further analysis of the spectrum of Aldebaran A did not show any variation correlated to the 643-day radial velocity oscillation, which would be expected if the cause was intrinsic. The best orbital solution was found to be around 653.8 days with an eccentricity of 0.182, and a lower mass limit of 11 Jupiter masses. The high value for the minimum mass means that it is likely that the object, if it exists, exceeds 13 Jupiter masses and is therefore a brown dwarf. However it is possible that the oscillation is due to a combination of pulsations, and as of 2006^[update], this companion has not been confirmed.^[6]

Etymology and cultural significance

Ancient cultures

The name Aldebaran comes from the Arabic (الدبران al-dabarān) meaning "the follower" and refers to the way the star follows the Pleiades star cluster in its nightly journey across the sky. In Persia it was known as Sadvis and Kugard.^[7] The Romans called it Palilicium, and it is known as 畢宿五 (Bìxiùwŭ, the Fifth Star of the Net) in Chinese. Aldebaran is identified as the lunar mansion Rohini in Hindu astronomy and as one of the twenty-seven daughters of Daksha and the wife of the god Chandra.

Gnostic Neo-Nazis

An esoteric neo-Nazi sect headquartered in Vienna, Austria called the Tempelhofgesellschaft, founded in the early 1990s, teaches a form of Gnosticism called Marcionism^{[citation needed]}. They distribute pamphlets claiming that the Aryan race originally came to Atlantis from the star Aldebaran (this information is supposedly based on "ancient Sumerian manuscripts"). They maintain that the Aryans from Aldebaran derive their power from the vril energy of the Black Sun. They teach that since the Aryan race is of extraterrestrial origin it has a divine mission to dominate all the other races. It is believed by adherents of this religion that an enormous space fleet is on its way to Earth from Aldebaran which, when it arrives, will join forces with the Nazi Flying Saucers from Antarctica to establish the Western Imperium. ^[8]

Inuit culture

In Inuit astronomy, Aldebaran is called "Spirit of a Polar Bear".

Italian witchcraft

In the religion of Stregheria, Aldebaran is a fallen angel and quarter guardian of the eastern gate.

Literature

Aldebaran is referred to in Edmund Spenser's The Faerie Queene (1590), book one, canto three, stanza 16:

Now when Aldeboran was mounted hye

Aboue the shinie Cassiopeia chaire (I.III.16.1-2)

In American horror writer H. P. Lovecraft's Cthulhu Mythos, Hastur resides in the Hyades cluster, and is signified by Aldebaran being above the horizon. When Aldebaran is visible, Hastur's eye is said to be upon all it oversees.

Mexican culture

For the Seris of northwestern Mexico, this star is providing light for the seven women giving birth (Pleiades). It has three different names: Hant Caalajc Ipápjö, Queeto, and Azoj Yeen oo Caap ("star that goes ahead"). The lunar month corresponding to October is called Queeto yaao "Aldebaran's path".^[9]

Native American culture

For the Dakotas (a branch of the Native American Sioux tribe), Aldebaran took on a heroic aspect. The young star was the child of the sun and the lady Blue Star. One day, he desired to hunt the white buffalo (the Pleiades). After he pulled up a sapling to make a spear, a hole was made in the ground and he could see all the people of Earth down below. The white buffalo took this chance to push him through. He was found by an old woman and was to be known as Old Woman's Grandson. On Earth, he killed many strange monsters that had been troubling the Native Americans; one monster of which was a serpent that caused drought. The young hero killed the serpent, releasing a great stream of water that became the Mississippi River. In time, Old Woman's Grandson remembered the white buffalo and returned to hunting him in the sky to fulfill his destiny.

Music

Reference to Aldebaran appears in the The Rolling Stones song "2000 Light Years from Home" from the 1967 psychedelic rock album Their Satanic Majesties Request. The Welsh-born Dark Ambient musician Brian Williams (Lustmord) has a track entitled "Aldebaran of the Hyades" on his 1994 album The Place where the Black Stars Hang. Enya included a song named "Alderbaran" on her first album, Enya (later re-released as The Celts). Austrian musician B. Fleischmann includes a song called "Aldebaran Waltz" in his 2006 album, The Humbucking Coil.

Aldebaran is also the title of a song by Essra Mohawk, and is included on her album Revelations Of The Secret Diva.

Games

In the mmorpg Ragnarok Online, one of the imaginary world's cities has the name Al de Baran. The players usually refer to the city as Aldebaran, or simpler "Alde".

Films and series

In the Star Trek television series, a whole system named Aldebaran got a role. Aldebaran III - Third planet in the Aldebaran star system. Longtime Federation member planet on which Janet and Theodore Wallace performed experiments using carbohydrate compounds to slow the aging of plants. It is location of the Aldebaran Music School. Grand Nagus Zek's nephew Belongo was once detained on Aldebaran III by Starfleet. Dr. Ira Graves, who cheated death by uploading his consciousness into Lt. Cmdr. Data, wanted to flee to a location in the Aldebaran system, so he could live on with his love, Kareen Brianon. The Aldebaran system is the home of a particularly tight-mouthed creature called the Aldebaran Shellmouth. Scotty and Picard share a bottle of Aldebaran whiskey.

See also

• Aldebaran in fiction
• Aldebaran in astrology
• Iota Draconis
• Pioneer 10
• Pollux

References

External links

• "Gl 171.1A". ARICNS. http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00382.htm. Retrieved 2005-11-14. 
• "Aldebaran 2". SolStation. http://www.solstation.com/stars2/aldebaran.htm. Retrieved 2005-11-14. 
• "Aldebaran". Extrasolar Visions. http://www.extrasolar.net/startour.asp?StarCatId=&StarId=28. Retrieved 2008-06-09. 
• "Aldebaran b". Extrasolar Visions. http://www.extrasolar.net/planettour.asp?StarCatId=&PlanetId=36. Retrieved 2008-06-09. 

Coordinates: 04^h 35^m 55.2^s, +16° 30′ 33″