HD 102117
HD 102117 or Uklun /ˈʌklən/ is a star in the southern constellation of Centaurus. With an apparent visual magnitude of 7.47,[2] 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,[1] having come to within 43.9 light-years some 692,000 years ago.[2] It has one known planet.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 11h 44m 50.46084s[1] |
| Declination | –58° 42′ 13.3564″[1] |
| Apparent magnitude (V) | 7.47[2] |
| Characteristics | |
| Spectral type | G6V[3] |
| B−V color index | 0.721±0.009[2] |
| Variable type | Constant[4] |
| Astrometry | |
| Radial velocity (Rv) | +49.64±0.13[1] km/s |
| Proper motion (μ) | RA: –63.555[1] mas/yr Dec.: –70.439[1] mas/yr |
| Parallax (π) | 25.2369 ± 0.0409 mas[1] |
| Distance | 129.2 ± 0.2 ly (39.62 ± 0.06 pc) |
| Absolute magnitude (MV) | 4.48[2] |
| 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 | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
The stellar classification of HD 102117 is G6V,[8] 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
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').[9]
| 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 | — | — |
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- 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, S2CID 119257644
- "HD 102117". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-28.
- 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.
- 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
- 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.
- "SPOCS I", Exoplanets, Yale University, retrieved 2012-01-31
- 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.
- "Pitcairn Islands". NameExoworlds. Retrieved 2019-12-30.
- 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.
External links
- "HD 102117". Exoplanets. Archived from the original on 2012-03-04. Retrieved 2009-05-23.
