HD 156279 is a star with a pair of orbiting exoplanets[8] located in the northern constellation of Draco.[1] It has various alternate designations, including HIP 84171 and BD+63 1335. Parallax measurements yield a distance of 118 light years from the Sun,[2] but it is drifting closer with a radial velocity of −20 km/s.[5] Despite an absolute magnitude of 5.25,[1] at that distance the star is too faint to be visible to the naked eye with an apparent visual magnitude of 8.17.[3] It is presumed to be a single star, as in 2019 all imaging surveys have failed to find any stellar companions.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco[1] |
| Right ascension | 17h 12m 23.204816s[2] |
| Declination | +63° 21′ 07.531205″[2] |
| Apparent magnitude (V) | 8.167±0.013[3] |
| Characteristics | |
| Evolutionary stage | main-sequence[4] |
| Spectral type | K0[3] or G6[4] |
| Apparent magnitude (R) | 7.60[1] |
| Apparent magnitude (G) | 7.8657[2] |
| Apparent magnitude (J) | 6.677±0.018[1] |
| B−V color index | 0.801±0.014[1] |
| Astrometry | |
| Radial velocity (Rv) | −20.144±0.161[5] km/s |
| Proper motion (μ) | RA: −1.879±0.024 mas/yr[2] Dec.: 160.429±0.027 mas/yr[2] |
| Parallax (π) | 27.6756 ± 0.0200 mas[2] |
| Distance | 117.85 ± 0.09 ly (36.13 ± 0.03 pc) |
| Absolute magnitude (MV) | 5.25[1] |
| Details | |
| Mass | 0.93±0.02[6] M☉ |
| Radius | 0.94±0.02[6] R☉ |
| Luminosity | 0.70±0.01[6] L☉ |
| Surface gravity (log g) | 4.45±0.03[6] cgs |
| Temperature | 5,449±31[6] K |
| Metallicity [Fe/H] | 0.14±0.01[3] dex |
| Rotational velocity (v sin i) | 2.51±1[4] km/s |
| Age | 7.4±2.2[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of HD 156279 has a stellar classification of G6[4] or K0,[3] depending on the study. Hence it presents as an ordinary main sequence star[4] of the late G-type or early K-type. The star has 93% of the mass of the Sun and 94% of the Sun's radius. HD 156279 is roughly seven[6] billion years old and is spinning with a projected rotational velocity of 2.5 km/s.[4] Based on the abundance of iron, this star is slightly enriched in heavy elements, having 140% of the solar abundance.[3] It is radiating 70%[6] of the luminosity of the Sun from its photosphere at an effective temperature of 5,449 K.[6]
Planetary system
editOrbiting HD 156279 are two superjovian planets, the inner HD 156279 b (discovered in 2011)[4] and outer HD 156279 c (discovered in 2016).[8] In 2022, the inclination and true mass of HD 156279 c were measured via astrometry.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 9.50+0.31 −0.32 MJ |
0.5041+0.0082 −0.0085 |
133.4031+0.0037 −0.0040 |
0.64779+0.00068 −0.00066 |
— | — |
| c | 9.750+1.319 −0.605 MJ |
5.486+0.219 −0.240 |
4818.3+44.5 −43.1 |
0.261±0.006 | 74.699+36.999 −10.533° |
— |
References
edit- ^ a b c d e f g 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 c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g Biller, B.; et al. (2019), "A high binary fraction for the most massive close-in giant planets and brown dwarf desert members", Monthly Notices of the Royal Astronomical Society, 485 (4): 4967–4996, arXiv:1903.02332, Bibcode:2019MNRAS.485.4967F, doi:10.1093/mnras/stz671, S2CID 84180618.
- ^ a b c d e f g Díaz, Rodrigo F.; et al. (2012), "The SOPHIE search for northern extrasolar planets IV. Massive companions in the planet-brown dwarf boundary", Astronomy & Astrophysics, A113: 538, arXiv:1111.1168, Bibcode:2012A&A...538A.113D, doi:10.1051/0004-6361/201117935, S2CID 55322205.
- ^ a b Carrera, R.; et al. (February 2022), "OCCASO. IV. Radial velocities and open cluster kinematics", Astronomy & Astrophysics, 658, arXiv:2110.02110, Bibcode:2022A&A...658A..14C, doi:10.1051/0004-6361/202141832, A14.
- ^ a b c d e f g h i Bonfanti, A.; et al. (2016), "Age consistency between exoplanet hosts and field stars", Astronomy & Astrophysics, 585: 14, arXiv:1511.01744, Bibcode:2016A&A...585A...5B, doi:10.1051/0004-6361/201527297, S2CID 53971692, A5.
- ^ "HD 156279". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 13 October 2020.
- ^ a b Bryan, Marta L.; et al. (2016), "Statistics of long period gas giant planets in known planetary systems", The Astrophysical Journal, 821 (2): 89, arXiv:1601.07595, Bibcode:2016ApJ...821...89B, doi:10.3847/0004-637X/821/2/89, S2CID 19709252.
- ^ a b Feng, Fabo; Butler, R. Paul; et al. (August 2022), "3D Selection of 167 Substellar Companions to Nearby Stars", The Astrophysical Journal Supplement Series, 262 (21): 21, arXiv:2208.12720, Bibcode:2022ApJS..262...21F, doi:10.3847/1538-4365/ac7e57, S2CID 251864022.
- ^ "HD 156279 Overview", NASA Exoplanet Archive, California Institute of Technology, retrieved 2024-01-10.