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.
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 | — | — |