HD 147018 is a star in the southern constellation of Triangulum Australe.[5] It has a yellow-orange hue with an apparent visual magnitude of 8.30,[2] which is too faint to be seen with the naked eye but can be viewed with a small telescope. The star is located at a distance of 132 light years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −27.5 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Triangulum Australe |
| Right ascension | 16h 23m 00.14702s[1] |
| Declination | −61° 41′ 19.5629″[1] |
| Apparent magnitude (V) | 8.30[2] |
| Characteristics | |
| Spectral type | G8/K0V[3] |
| Apparent magnitude (B) | 9.063[2] |
| Apparent magnitude (J) | 6.963±0.023[2] |
| Apparent magnitude (H) | 6.640±0.044[2] |
| Apparent magnitude (K) | 6.571±0.021[2] |
| B−V color index | 0.763±0.002[2] |
| Astrometry | |
| Radial velocity (Rv) | −27.5±0.3[2] km/s |
| Proper motion (μ) | RA: −177.498[1] mas/yr Dec.: −316.244[1] mas/yr |
| Parallax (π) | 24.7079 ± 0.0434 mas[1] |
| Distance | 132.0 ± 0.2 ly (40.47 ± 0.07 pc) |
| Absolute magnitude (MV) | 5.14[2] |
| Details[4] | |
| Mass | 0.927±0.031 M☉ |
| Radius | 0.94±0.02[1] R☉ |
| Luminosity | 0.712±0.002[1] L☉ |
| Surface gravity (log g) | 4.38±0.16 cgs |
| Temperature | 5,441±55 K |
| Metallicity [Fe/H] | 0.10±0.05 dex |
| Rotational velocity (v sin i) | 1.56 km/s |
| Age | 6.36±4.33 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The stellar classification of HD 147018 is G8/K0V[3] or G9V,[4] matching a late G-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly six billion years old and is spinning with a projected rotational velocity of 1.56 km/s. The star has 93%[4] of the mass of the Sun and 94%[1] of the Sun's radius. The metallicity, or abundance of heavier elements, is higher than in the Sun.[4] The star is radiating 71%[1] of the luminosity of the Sun from its photosphere at an effective temperature of 5,441 K.[4]
In August 2009, two extrasolar planets, HD 147018 b and HD 147018 c, were reported to be orbiting this star. The planets were found using the radial velocity method, using the CORALIE spectrograph at La Silla Observatory, Chile.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥2.12±0.07 MJ | 0.2388±0.0039 | 44.236±0.008 | 0.4686±0.0081 | — | — |
| c | ≥6.56±0.32 MJ | 1.922±0.039 | 1,008±18 | 0.133±0.011 | — | — |
See also
editReferences
edit- ^ a b c d e f g h i j 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 f g h i j 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 Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ a b c d e f g Segransan, D.; et al. (February 2010), "The CORALIE survey for southern extrasolar planets. XVI. Discovery of a planetary system around HD 147018 and of two long period and massive planets orbiting HD 171238 and HD 204313", Astronomy and Astrophysics, 511: 6, arXiv:0908.1479, Bibcode:2010A&A...511A..45S, doi:10.1051/0004-6361/200912136, S2CID 8864844, A45
- ^ a b "HD 147018". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-12.