Epsilon Reticuli

Starbox begin
name = Epsilon Reticuli (A / B)Starbox observe
epoch = J2000
constell = Reticulum
ra = RA|4|16|29.03
dec = DEC|-59|18|07.76
appmag_v = 4.44 / 12.5Starbox character
class = K2IVa / D
r-i =
v-r =
b-v =
u-b =
variable = Starbox astrometry
radial_v =
prop_mo_ra =
prop_mo_dec =
parallax =
p_error =
parallax_footnote =
dist_ly = 59.45
dist_pc = 18.23
space_v_u =
space_v_v =
space_v_w =
absmag_v = Starbox catalog
names = HR 1355, HD 27442, HIP 19921Starbox reference
Simbad = HD+27442
ARICNS =

Epsilon Reticuli (in the literature, HD 27442) is a binary system approximately 59 light-years away in the constellation of Reticulum. The primary star is an orange subgiant star, while the secondary star is a white dwarf star. The primary star should be easily visible without optical aid under dark skies in southern hemisphere. As of 2000, an extrasolar planet has been confirmed to be orbiting the primary star in the system.

Star system

The primary star, Epsilon Reticuli A, is an orange subgiant 20% more massive than our Sun. Being a subgiant it is ceasing or has already ceased fusing hydrogen in its core. Soon the star will swell up and become a red giant. Despite its advanced stage, it cannot be much older than the Sun.

The companion star, Epsilon Reticuli B, is a white dwarf star located around 240 AU from Epsilon Reticuli A. [Cite journal | url=http://www.aanda.org/articles/aa/abs/2007/44/aa7046-06/aa7046-06.html | title=Characterization of the long-period companions of the exoplanet host stars: HD 196885, HD 1237 and HD 27442 | author=Chauvin "et al." | journal=Astronomy and Astrophysics | year=2007 | volume=475 | issue=2 | page=723-727 | doi=10.1051/0004-6361:20067046 | format=abstract ( [http://arxiv.org/abs/0710.5918 web preprint] )] It has a surface temperature between 9000 and 17000 K.

Planetary system

On December 11 2000, a team of astronomers announced the discovery of a planet Epsilon Reticuli b. [cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/321467 | author=Butler "et al." | title=Two New Planets from the Anglo-Australian Planet Search | journal=The Astrophysical Journal | volume=555 | issue=1 | year=2001 | pages=410–417 | doi=10.1086/321467 ] With a minimum mass of 1.17 that of Jupiter and a similar radius, the planet moves around Epsilon Reticuli with an average separation of 1.16 AUs. The eccentricity of the planet is extremely low (at 0.06), and orbits around the star every 418 days (or 1.13 years).

There could 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]

PlanetboxOrbit
exoplanet = b
mass = >1.56±0.14
period = 428.1±1.1
semimajor = 1.271±0.073
eccentricity = 0.060±0.043

References

External links

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