| 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 |
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]
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
[edit]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 | — | — |
See also
[edit]References
[edit]- ^ a b c d e f g 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.
- ^ a b c d e 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
- ^ a b "HD 102117". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-28.
- ^ 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.
- ^ 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
- ^ 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.
- ^ a b c d e "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
[edit]- "HD 102117". Exoplanets. Archived from the original on 2012-03-04. Retrieved 2009-05-23.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction