Iota Horologii

Starbox begin
name = Iota HorologiiStarbox observe
epoch = J2000.0
constell = Horologium
ra = RA|02|42|31.65
dec = DEC|-50|48|12.29
appmag_v = +5.40
appmag_b = +5.97 Starbox character
class = G0Vp
b-v = 0.57
variable = none Starbox astrometry
radial_v = 15.5
prop_mo_ra = 333.73
prop_mo_dec = 219.21
parallax = 58.00 ± 0.55 [Hipparcos]
p_error = 0.55
dist_ly = 50.6
dist_pc = 16.8
absmag_v = 4.27 Starbox detail
age = 625 ± 5 Myrcite arXiv | title=The exoplanet-host star iota Horologii: an evaporated member of the primordial Hyades cluster. |author=S. Vauclair "et al." | year=2008 |eprint=0803.2029v1 |class=astro-ph, announced in cite web| url=http://www.astronomynow.com/Thedriftingstar.html| title=The Drifting Star|author=Emily Baldwin|accessdate=2008-04-18]
metal = [Fe/H] = 0.14-0.19
mass = 1.25 ± 0.01
radius = 1.5cite web|url=http://www.solstation.com/stars2/iotahoro.htm|title=Iota Horologii|accessdate=2008-05-28|publisher=SolStation]
rotation = 8.6 days
luminosity = 1.8
temperature = 6125 ± 30 Starbox catalog
names = HR 810, HD 17051, Gliese 108 Starbox reference
Simbad = HD+17051

Iota Horologii (ι Hor / ι Horologii) is a solar twin, yellow dwarf star approximately 56 light-years away in the constellation of Horologium (the Pendulum Clock). The star is classified as a G0Vp yellow dwarf (it has previously been classified as G3 and a subgiant [IV] ). It has a mass and radius larger than the Sun, and is about 50% more luminous.

As of 1998, a single extrasolar planet is known orbiting Iota Horologii. Because the planet orbits in a near Earth orbit, Iota Horologii was ranked 69th in the list of candidates for NASA's planned Terrestrial Planet Finder mission. In 2000, a dust disc was announced around the star, yet this was later determined to be an instrumental artifact.

Distance and visibility

Since Iota Horologii is in the minor constellation of Horologium and that it is quite dim in the sky, the star has not been given a traditional name. Inside the constellation, Iota Horologii is placed near the stars Mu Horologii and R Horologii (despite not being close to them in distance).

Spectrographic analysis indicates the star must have formed together with the stars of the Hyades cluster (~625 million years ago) but must have slowly drifted away, being presently more than 130 light-years away from its original birthplace. This also means that the amount of metals present in the star is due to the original cloud from which it formed and not because it engulfed planetary material.

In its current position, Iota Horologii is closest to the star Chi Eridani (a yellow subgiant), approximately 7 light-years away. The closest planetary systems to Iota Horologii is HD 10647 (a yellow dwarf), approximately 9 light-years away; and Epsilon Reticuli (an orange subgiant), approximately 16 light-years away. Other star systems close to Iota Horologii include Nu Phoenicis and Zeta Reticuli.

Planetary system

As of 1998, Iota Horologii is known to have an extrasolar planet. The planet designated Iota Horologii b was the result of a long-term survey of forty solar-type stars that was begun in November 1992.

Observations of Iota Horologii in October 2000 appeared to show a dust disc around the star at a distance of 65 AU, similar to the Kuiper belt in our solar system. However further analysis revealed the dust disc to be an instrumental artifact and the discovery claim was retracted.

There could on the other hand be an Earth sized planet in its Trojan field. [cite journal |journal=Astronomy & Astrophysics |DOI=10.1051/0004-6361:20077994 | volume=474|page=1023-1029 |title=Survey of the stability region of hypothetical habitable Trojan planets |author=R. Schwarz, R. Dvorak, Á. Süli, and B. Érdi | year=2007: HD 93083, HD 17051, HD 28185, HD 27442, HD 188015, HD 99109, HD 221287]

Based on residuals in the radial velocity curve, a planet in an eccentric orbit with a period of approximately 600 days was proposed, however this was not confirmed and it seems likely that the effect was due to activity on Iota Horologii itself.

OrbitboxPlanet
exoplanet = b
mass = >2.24 ± 0.13
period = 311.3 ± 1.3
semimajor = 0.91
eccentricity = 0.22 ± 0.06

See also

* Iota Horologii in fiction
* Gliese 570

References

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External links

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