# HD 102117

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Star in the constellation Centaurus

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] Distance 128.65 ± 0.09 ly (39.44 ± 0.03 pc) Absolute magnitude (MV) 4.48[1] Details Mass 1.37±0.130 M☉[5] 1.03±0.05[6] M☉ Radius 1.27[7] R☉ Luminosity 1.54[7] L☉ Surface gravity (log g) 4.37±0.06[7] cgs Temperature 5,695±44[5] K Metallicity [Fe/H] 0.30±0.03[6] dex Rotational velocity (v sin i) 0.88±0.5[7] km/s Age 5.3±3.4[5] Gyr Other designations Uklun, CD−58°4207, HD 102117, HIP 57291, SAO 239348[8] Database references SIMBAD data Exoplanet Archive data

**HD 102117** or **Uklun** [/ˈʌklən/](https://en.wikipedia.org/wiki/Help:IPA/English) is a [star](/source/Star) in the southern [constellation](/source/Constellation) of [Centaurus](/source/Centaurus). With an [apparent visual magnitude](/source/Apparent_visual_magnitude) of 7.47,[1] it is too dim to be seen without [binoculars](/source/Binoculars) or a small [telescope](/source/Telescope). It is located at a distance of approximately 129 [light-years](/source/Light-year) from the [Sun](/source/Sun) based on [parallax](/source/Stellar_parallax). HD 102117 is drifting further away with a [radial velocity](/source/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](/source/Stellar_classification) of HD 102117 is G6V,[9] which matches the [spectrum](/source/Stellar_spectrum) of an ordinary [G-type main-sequence star](/source/G-type_main-sequence_star). It is roughly five[5] billion years old and is spinning with a [projected rotational velocity](/source/Projected_rotational_velocity) of 0.9 km/s.[7] The star shows only a low level of [chromospheric activity](/source/Chromospheric_activity)[6] and is [photometrically](/source/Photometry_(astronomy)) stable,[4] meaning it doesn't vary significantly in brightness. It appears [metal-enriched](/source/Metallicity),[4] showing a higher abundance of heavy elements compared to the Sun.

## Planetary system

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

HD 102117, and its planet HD 102117b, were chosen as part of the 2019 [NameExoWorlds](/source/NameExoWorlds) campaign organised by the [International Astronomical Union](/source/International_Astronomical_Union), which assigned each country a star and planet to be named. HD 102117 was assigned to [Pitcairn Islands](/source/Pitcairn_Islands). The winning proposal named the star **Uklun**, from the word *aklan* 'we/us' in the [Pitcairn language](/source/Pitcairn_language), and the planet **Leklsullun** [/lɛkəlsʌlən/](https://en.wikipedia.org/wiki/Help:IPA/English), 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

- [List of extrasolar planets](/source/List_of_extrasolar_planets)

- [HARPS spectrograph](/source/HARPS_spectrograph)

- [Anglo-Australian Planet Search](/source/Anglo-Australian_Planet_Search)

## References

1. ^ [***a***](#cite_ref-Anderson_Francis_2012_1-0) [***b***](#cite_ref-Anderson_Francis_2012_1-1) [***c***](#cite_ref-Anderson_Francis_2012_1-2) [***d***](#cite_ref-Anderson_Francis_2012_1-3) [***e***](#cite_ref-Anderson_Francis_2012_1-4) [***f***](#cite_ref-Anderson_Francis_2012_1-5) Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". *[Astronomy Letters](/source/Astronomy_Letters)*. **38** (5): 331. [arXiv](/source/ArXiv_(identifier)):[1108.4971](https://arxiv.org/abs/1108.4971). [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..331A](https://ui.adsabs.harvard.edu/abs/2012AstL...38..331A). [doi](/source/Doi_(identifier)):[10.1134/S1063773712050015](https://doi.org/10.1134%2FS1063773712050015). [XHIP record for this object](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-ref=VIZ681510a8389ecb&-out.src=V%2F137D%2FXHIP&-nav=cat%3AV%2F137D%26tab%3A{V%2F137D%2FXHIP}%26key%3Asource%3DV%2F137D%2FXHIP%26HTTPPRM%3A&-source=V%2F137D%2FXHIP&-out=HIP&HIP=57291&-out=Comp&-out=Gr&-out=RAJ2000&-out=DEJ2000&-out=Dist&-out=X&-out=Y&-out=Z&-out=SpType&-out=Simbad&-out=Hpmag&-out=Lum&-out=Cst) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-GaiaDR3_2-0) [***b***](#cite_ref-GaiaDR3_2-1) [***c***](#cite_ref-GaiaDR3_2-2) [***d***](#cite_ref-GaiaDR3_2-3) [***e***](#cite_ref-GaiaDR3_2-4) [***f***](#cite_ref-GaiaDR3_2-5) [***g***](#cite_ref-GaiaDR3_2-6) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D5341673851394297600%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-houk1975_3-0)** Houk, N.; Cowley, A. P. (1975). "University of Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume I". [Bibcode](/source/Bibcode_(identifier)):[1975mcts.book.....H](https://ui.adsabs.harvard.edu/abs/1975mcts.book.....H). {{[cite journal](https://en.wikipedia.org/wiki/Template:Cite_journal)}}: Cite journal requires |journal= ([help](https://en.wikipedia.org/wiki/Help:CS1_errors#missing_periodical))

1. ^ [***a***](#cite_ref-Tinney2005_4-0) [***b***](#cite_ref-Tinney2005_4-1) [***c***](#cite_ref-Tinney2005_4-2) [***d***](#cite_ref-Tinney2005_4-3) Tinney, C. G.; et al. (2005). "Three Low-Mass Planets from the Anglo-Australian Planet Search". *The Astrophysical Journal*. **623** (2): 1171–1179. [Bibcode](/source/Bibcode_(identifier)):[2005ApJ...623.1171T](https://ui.adsabs.harvard.edu/abs/2005ApJ...623.1171T). [CiteSeerX](/source/CiteSeerX_(identifier)) [10.1.1.491.2941](https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.491.2941). [doi](/source/Doi_(identifier)):[10.1086/428661](https://doi.org/10.1086%2F428661). [S2CID](/source/S2CID_(identifier)) [12515735](https://api.semanticscholar.org/CorpusID:12515735).

1. ^ [***a***](#cite_ref-apj22159_1_141_5-0) [***b***](#cite_ref-apj22159_1_141_5-1) [***c***](#cite_ref-apj22159_1_141_5-2) [***d***](#cite_ref-apj22159_1_141_5-3) 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](/source/Bibcode_(identifier)):[2005ApJS..159..141V](https://ui.adsabs.harvard.edu/abs/2005ApJS..159..141V), [doi](/source/Doi_(identifier)):[10.1086/430500](https://doi.org/10.1086%2F430500)

1. ^ [***a***](#cite_ref-Lovis2005_6-0) [***b***](#cite_ref-Lovis2005_6-1) [***c***](#cite_ref-Lovis2005_6-2) [***d***](#cite_ref-Lovis2005_6-3) [***e***](#cite_ref-Lovis2005_6-4) 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](/source/ArXiv_(identifier)):[astro-ph/0503660](https://arxiv.org/abs/astro-ph/0503660). [Bibcode](/source/Bibcode_(identifier)):[2005A&A...437.1121L](https://ui.adsabs.harvard.edu/abs/2005A&A...437.1121L). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20052864](https://doi.org/10.1051%2F0004-6361%3A20052864). [S2CID](/source/S2CID_(identifier)) [119492030](https://api.semanticscholar.org/CorpusID:119492030).

1. ^ [***a***](#cite_ref-spocs_7-0) [***b***](#cite_ref-spocs_7-1) [***c***](#cite_ref-spocs_7-2) [***d***](#cite_ref-spocs_7-3) [***e***](#cite_ref-spocs_7-4) ["SPOCS I"](https://web.archive.org/web/20120309110733/http://exoplanets.astro.yale.edu/science/analysis/spocs.php), *Exoplanets*, [Yale University](/source/Yale_University), archived from [the original](http://exoplanets.astro.yale.edu/science/analysis/spocs.php) on 2012-03-09, retrieved 2012-01-31

1. **[^](#cite_ref-SIMBAD_8-0)** ["HD 102117"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+102117). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2021-01-28.

1. **[^](#cite_ref-Houk1979_9-0)** 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](/source/Bibcode_(identifier)):[1978mcts.book.....H](https://ui.adsabs.harvard.edu/abs/1978mcts.book.....H).

1. **[^](#cite_ref-NameExoWorlds_10-0)** ["Pitcairn Islands"](http://www.nameexoworlds.iau.org/pitcairn-islands). *NameExoworlds*. Retrieved 2019-12-30.

1. **[^](#cite_ref-Butler2006_11-0)** Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". *The Astrophysical Journal*. **646** (1): 505–522. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0607493](https://arxiv.org/abs/astro-ph/0607493). [Bibcode](/source/Bibcode_(identifier)):[2006ApJ...646..505B](https://ui.adsabs.harvard.edu/abs/2006ApJ...646..505B). [doi](/source/Doi_(identifier)):[10.1086/504701](https://doi.org/10.1086%2F504701). [S2CID](/source/S2CID_(identifier)) [119067572](https://api.semanticscholar.org/CorpusID:119067572).

## External links

- ["HD 102117"](https://web.archive.org/web/20120304130302/http://media4.obspm.fr/exoplanets/base/etoile.php?nom=HD+102117). *Exoplanets*. Archived from [the original](http://media4.obspm.fr/exoplanets/base/etoile.php?nom=HD+102117) on 2012-03-04. Retrieved 2009-05-23.

v t e Constellation of Centaurus List of stars in Centaurus Centaurus in Chinese astronomy Stars Bayer α A (Rigil Kentaurus) B (Toliman) C (Proxima Centauri) β (Hadar) γ δ ε ζ (Leepwal) η θ (Menkent) ι (Kulou) κ λ μ ν (Heng) ξ1 ξ2 ο1 ο2 π ρ σ τ υ1 υ2 φ χ ψ x1 x2 C3 D E F G H J K M N Q Flamsteed 1 (i) 2 (g) 3 (k) 4 (h) Variable R T V Y RR SV SX BV DY UY V346 V553 V744 V752 V761 (a) V763 (C1) V766 V779 (Krzemiński's star) V803 V810 V816 (Przybylski's Star) V831 V842 V885 V886 V863 V1032 V1369 V1400 V1935 HR 4460 (A) 4466 (C2) 4499 4522 4523 4537 (j) 4546 (B) 4721 4748 (u) 4796 4817 (l) 4831 (w) 4874 (p) 4888 (e) 4889 (n) 4940 (f) 4979 4989 5006 (r) 5041 (m) 5089 (d) 5174 (z) 5222 (y) 5224 5241 5297 5358 (v) 5371 5471 (b) 5485 (c1) 5489 (c2) HD 97413 98176 100453 101581 101930 102117 (Uklun) 103197 107914 108236 109749 110113 113538 113766 114386 114729 115600 116434 (Matza) 117207 117618 (Dofida) 117939 120411 121228 121504 124448 (Popper's Star) 125072 125595 131399 Other 2MASS J1126−5003 2M1207 Gaia BH2 HD 131399 Ab PSR B1259−63 PSR J1311−3430 TOI-763 WASP-15 (Nyamien) WASP-41 WASP-42 WASP-167/KELT-13 Exoplanets 2M1207b b Centauri b HD 101930 b HD 102117 b (Leklsullun) HD 103197 b HD 109749 b HD 113538 b c HD 114386 b HD 114729 b HD 117207 b HD 117618 b (Noifasui) HD 121504 b HIP 65426 b (Najsakopajk) HIP 67522 b NGTS-13b Proxima Centauri b c d WASP-15b (Asye) Star clusters NGC 3766 4230 4507 5281 5286 5316 5460 5617 5662 Other IC 2944 ω Centauri Scorpius–Centaurus association Stock 16 Nebulae NGC 3918 5307 Other Boomerang Nebula Fleming 1 G292.0+1.8 G306.3-0.9 Gum 41 IC 2944 IRAS 13208−6020 RCW 79 RCW 86 Southern Crab Nebula SuWt 2 Galaxies NGC 3557 3568 3749 3783 4444 4603 4622 4650A 4683 4696 4706 4709 4729 4730 4743 4744 4909 4930 4945 4976 5011 A 5026 5064 5082 5090 5091 5102 5114 5121 5128 (Centaurus A) 5161 5206 5253 5266 5291 5398 5408 5419 5483 5516 Other ESO 269-57 ESO 325-4 ESO 383-76 ESO 444-46 Fourcade-Figueroa Object IC 3370 IC 4214 IC 4329A IRAS 13224−3809 J1144−4308 LEDA 677373 PKS 1144−379 PKS 1353−341 PKS 1424−418 Galaxy clusters Abell S740 Centaurus Cluster Shapley Supercluster Astronomical events GW190521 SN 185 SN 1895B (Z) SN 1972E SN 1986G J1407b SN 2019so Category

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Adapted from the Wikipedia article [HD 102117](https://en.wikipedia.org/wiki/HD_102117) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/HD_102117?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.