HD 190647
HD 190647 is a yellow-hued star with an exoplanetary companion, located in the southern constellation of Sagittarius. It has an apparent visual magnitude of 7.78,[2] making this an 8th magnitude star that is much too faint to be readily visible to the naked eye. The star is located at a distance of 178 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −40 km/s.[1] It is also called HIP 99115.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 20h 07m 19.6698s[1] |
| Declination | −35° 32′ 19.0786″[1] |
| Apparent magnitude (V) | 7.78[2] |
| Characteristics | |
| Spectral type | G5V[3] |
| B−V color index | 0.743±0.002[2] |
| Variable type | Constant[4] |
| Astrometry | |
| Radial velocity (Rv) | −40.33±0.12[1] km/s |
| Proper motion (μ) | RA: −26.622±0.079[1] mas/yr Dec.: −206.859±0.053[1] mas/yr |
| Parallax (π) | 18.3287 ± 0.0495 mas[1] |
| Distance | 177.9 ± 0.5 ly (54.6 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.00[2] |
| Details | |
| Mass | 1.07±0.01[5] M☉ |
| Radius | 1.56±0.03[5] R☉ |
| Luminosity | 2.19±0.01[5] L☉ |
| Surface gravity (log g) | 4.07±0.02[5] cgs |
| Temperature | 5,630+48 −40[5] K |
| Metallicity [Fe/H] | 0.23[6] dex |
| Rotational velocity (v sin i) | 1.576[6] km/s |
| Age | 8.7±0.4[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The stellar classification of this star is G5V,[3] matching a G-type main-sequence star. However, the low gravity and high luminosity of this star may indicate it is slightly evolved. It is chrompsherically inactive with a slow rotation,[4] having a projected rotational velocity of 1.6 km/s.[6] The star's metallicity is high, with nearly 1.5 times the abundance of iron compared to the Sun.[4]
In 2007, a Jovian planet was found to be orbiting the star. It was detected using the radial velocity method with the HARPS spectrograph in Chile. The object is orbiting at a distance of 2.0 AU from the host star with a period of 2.84 years and an eccentricity (ovalness) of 0.18. As the inclination of the orbital plane is unknown, only a lower bound on the planetary mass can be made. It has a minimum mass 1.9 times the mass of Jupiter.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >1.9 ± 0.06 MJ | 2.07 ± 0.06 | 1038.1 ± 4.9 | 0.18 ± 0.02 | — | — |
See also
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.
- Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 3. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1982mcts.book.....H.
- Naef, M.; et al. (2007). "The HARPS search for southern extra-solar planets. IX. Exoplanets orbiting HD 100777, HD 190647, and HD 221287". Astronomy and Astrophysics. 470 (2): 721–726. arXiv:0704.0917. Bibcode:2007A&A...470..721N. doi:10.1051/0004-6361:20077361.
- Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (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.
- Costa Silva, A. R.; et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics. 634: 10. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. S2CID 209405391. A136.
- "HD 190647". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-11.