Pollux (star)

Starbox begin
name = PolluxStarbox image


caption = The position of Pollux within the constellation of Gemini.Starbox observe
epoch = J2000.0
constell = Gemini
ra = RA|07|45|19.4
dec = DEC|+28|01|35
appmag_v = 1.15Starbox character
class = K0IIIb
r-i =
v-r =
b-v = 1.00
u-b = 0.86
variable = "Suspected"Starbox astrometry
radial_v = +3.3
prop_mo_ra = −625.69
prop_mo_dec = −45.95
parallax = 96.74
p_error = 0.87
parallax_footnote =
dist_ly =
dist_pc =
space_v_u =
space_v_v =
space_v_w =
absmag_v = 1.09Starbox detail
source =
mass = 1.86
radius = 8.0
gravity =
luminosity = 32
temperature = 4,865
metal = 90% Sun
rotation = 38 days
age = Starbox catalog
names = Beta Geminorum, 78 Geminorum, BD+28°1463, GCTP 1826.00, Gliese 286, HD 62509, HIP 37826, HR 2990, LFT 548, LHS 1945, LTT 12065, SAO 79666Starbox reference
Simbad = HD+62509
ARICNS = 4c00589

Pollux, also cataloged as Beta Geminorum (β Gem / β Geminorum), is an orange giant star approximately 34 light-years away in the constellation of Gemini (the Twins). Pollux is the brightest star in the constellation (brighter than Castor (Alpha Geminorum). As of 2006, Pollux was confirmed to have an extrasolar planet orbiting it.

Naming

The name Pollux refers specifically to Castor and Pollux, the twin sons of Zeus and Leda. The star also bears Arabic name "Al-Ras al-Tau'am al-Mu'akhar",(الرأس التؤام المؤخر), literally, 'The Head of the Second Twin'. Historically, the Chinese recognized Pollux as "Yang", which in ancient philosophy was one of the two fundamental principles upon which all things depend. Castor and Pollux together correspond to the Nakshatra Punarvasu in Hindu astronomy.

Castor and Pollux are the two 'heavenly twin' stars giving the constellation Gemini (Latin, 'the twins') its name. Ironically, the two are nothing alike. Castor is a complex sextuple system comprised of hot, bluish-white A-type stars and dim red dwarfs, while Pollux is a single cooler yellow-orange giant. The name is traditionally thought by some people to carry the meaning 'much wine', since astrologers associate Pollux with prosperity and celebration with wine.

Stellar components

Pollux is an orange giant star of the spectral type of "K0IIIb". It has been calculated that the star has about 1.7 time more mass than the Sun, 8.8 times more radius, and 32 times more luminosity. Beginning around 1990, Pollux has been measured to be around 85 to 155 percent as enriched with elements heavier than hydrogen (based on its abundance of iron).

Because Pollux is more massive and more evolved than the Sun, it is thought that the star is likely to be much younger than the Sun. Pollux's high mass estimates suggest that it has not yet suffered substantial mass loss. It would then evolve to the first ascent of the red giant branch.

Planetary system

Announced on June 16 2006, the confirmation of the suspected extrasolar planet Pollux b was finally detected. Assuming that Pollux has more mass than the Sun, Pollux b has been calculated to have a minimum mass of 2.3 times that of Jupiter. The planet orbits Pollux at an average distance of 1.64 astronomical units in an almost circular orbit that takes approximately 590 days to complete. Pollux b is currently one of the few planets to be orbiting a star that is visible to the naked eye. The planet is also the only confirmed planet to secure the traditional name of its parent star.

PlanetboxOrbit begin
name = PolluxPlanetboxOrbit
exoplanet = b
mass = 2.3 ± 0.45
period = 589.64 ± 0.81
semimajor = 1.64 ± 0.27
eccentricity = 0.02 ± 0.03

See also

* Aldebaran
* Castor (star)
* Pollux in fiction

External links

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