HD 102117

HD 102117 / Uklun
Observation data
Epoch J2000      Equinox J2000
Constellation Centaurus[1]
Right ascension 11h 44m 50.46086s[2]
Declination −58° 42′ 13.3580″[2]
Apparent magnitude (V) 7.47[1]
Characteristics
Evolutionary stage subgiant[2]
Spectral type G6V[3]
B−V color index 0.721±0.009[1]
Variable type Constant[4]
Astrometry
Radial velocity (Rv)+49.52±0.12[2] km/s
Proper motion (μ) RA: −63.574 mas/yr[2]
Dec.: −70.331 mas/yr[2]
Parallax (π)25.3531±0.0178 mas[2]
Distance128.65 ± 0.09 ly
(39.44 ± 0.03 pc)
Absolute magnitude (MV)4.48[1]
Details
Mass1.37±0.130 M[5]
1.03±0.05[6] M
Radius1.27[7] R
Luminosity1.54[7] L
Surface gravity (log g)4.37±0.06[7] cgs
Temperature5,695±44[5] K
Metallicity [Fe/H]0.30±0.03[6] dex
Rotational velocity (v sin i)0.88±0.5[7] km/s
Age5.3±3.4[5] Gyr
Other designations
Uklun, CD−58°4207, HD 102117, HIP 57291, SAO 239348[8]
Database references
SIMBADdata
Exoplanet Archivedata

HD 102117 or Uklun /ˈʌklən/ is a star in the southern constellation of Centaurus. With an apparent visual magnitude of 7.47,[1] it is too dim to be seen without binoculars or a small telescope. It is located at a distance of approximately 129 light-years from the Sun based on parallax. HD 102117 is drifting further away with a radial velocity of +50 km/s,[2] having come to within 43.9 light-years some 692,000 years ago.[1] It has one known planet.[6]

The stellar classification of HD 102117 is G6V,[9] which matches the spectrum of an ordinary G-type main-sequence star. It is roughly five[5] billion years old and is spinning with a projected rotational velocity of 0.9 km/s.[7] The star shows only a low level of chromospheric activity[6] and is photometrically stable,[4] meaning it doesn't vary significantly in brightness. It appears metal-enriched,[4] showing a higher abundance of heavy elements compared to the Sun.

Planetary system

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In 2004, the Anglo-Australian Planet Search announced a planet orbiting the star.[4] A short time later the HARPS team also announced the presence of a planet around this star. Both groups detected this planet with the radial velocity method.[6]

HD 102117, and its planet HD 102117b, were chosen as part of the 2019 NameExoWorlds campaign organised by the International Astronomical Union, which assigned each country a star and planet to be named. HD 102117 was assigned to Pitcairn Islands. The winning proposal named the star Uklun, from the word aklan 'we/us' in the Pitcairn language, and the planet Leklsullun /lɛkəlsʌlən/, from the phrase lekl salan 'child/children' (lit. 'little person').[10]

The HD 102117 planetary system[11]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b / Leklsullun 0.172 ± 0.020 MJ 0.1532 ± 0.0088 20.8133 ± 0.0064 0.121 ±0.082

See also

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References

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  1. ^ a b c d e f Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. ^ a b c d e f g Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. ^ Houk, N.; Cowley, A. P. (1975). "University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0". Bibcode:1975mcts.book.....H. {{cite journal}}: Cite journal requires |journal= (help)
  4. ^ a b c d Tinney, C. G.; et al. (2005). "Three Low-Mass Planets from the Anglo-Australian Planet Search". The Astrophysical Journal. 623 (2): 1171–1179. Bibcode:2005ApJ...623.1171T. CiteSeerX 10.1.1.491.2941. doi:10.1086/428661. S2CID 12515735.
  5. ^ a b c d Valenti, Jeff A.; Fischer, Debra A. (July 2005), "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs", The Astrophysical Journal Supplement Series, 159 (1): 141–166, Bibcode:2005ApJS..159..141V, doi:10.1086/430500
  6. ^ a b c d e Lovis, C.; et al. (2005). "The HARPS search for southern extra-solar planets III. Three Saturn-mass planets around HD 93083, HD 101930 and HD 102117". Astronomy and Astrophysics. 437 (3): 1121–1126. arXiv:astro-ph/0503660. Bibcode:2005A&A...437.1121L. doi:10.1051/0004-6361:20052864. S2CID 119492030.
  7. ^ a b c d e "SPOCS I", Exoplanets, Yale University, archived from the original on 2012-03-09, retrieved 2012-01-31
  8. ^ "HD 102117". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-28.
  9. ^ Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H.
  10. ^ "Pitcairn Islands". NameExoworlds. Retrieved 2019-12-30.
  11. ^ Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID 119067572.
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