Astronomy:HD 90156
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Hydra[1] |
| Right ascension | 10h 23m 55.274s[2] |
| Declination | –29° 38′ 43.91″[2] |
| Apparent magnitude (V) | 6.92[1] |
| Characteristics | |
| Spectral type | G5 V[3] |
| Apparent magnitude (B) | 7.579 |
| Apparent magnitude (J) | 5.685±0.023[1] |
| Apparent magnitude (H) | 5.382±0.034[1] |
| Apparent magnitude (K) | 5.245±0.024[1] |
| B−V color index | 0.659±0.007[1] |
| Variable type | None[4] |
| Astrometry | |
| Radial velocity (Rv) | 26.958±0.0002[5] km/s |
| Proper motion (μ) | RA: –39.159[2] mas/yr Dec.: 99.302[2] mas/yr |
| Parallax (π) | 45.5628 ± 0.0214[2] mas |
| Distance | 71.58 ± 0.03 ly (21.95 ± 0.01 pc) |
| Absolute magnitude (MV) | 5.17[1] |
| Details | |
| Mass | 0.837±0.009[6] M☉ |
| Radius | 0.876±0.013[6] R☉ |
| Luminosity | 0.74±0.01[7] L☉ |
| Surface gravity (log g) | 4.40±0.02[6] cgs |
| Temperature | 5,599±12[4] K |
| Metallicity [Fe/H] | –0.24±0.01[4] dex |
| Rotational velocity (v sin i) | 0.817[8] km/s |
| Age | 4.4 Gyr[4] 8.1±3.8[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
HD 90156 is a star with an orbiting exoplanet in the constellation Hydra. Based on parallax measurements, it is located at a distance of 71.6 light years from the Sun.[2] The system is drifting further away with a heliocentric radial velocity of 27 km/s.[5] The apparent visual magnitude of this star is 6.92,[1] which is places it near the lower limit of visibility to the naked eye. A survey in 2015 ruled out the existence of any stellar companions at projected distances above 5 astronomical unit|AU.[10]
This star was designated as Gamma Antliae by Lacaille, and Gould intended to keep it in the Antlia constellation. However, the delineating of constellation boundaries in 1930 saw it transferred to Hydra.[11]
The spectrum of HD 90156 presents as a G-type main-sequence star with a stellar classification of G5 V[3] It is rotating slowly with a projected rotational velocity of 0.817,[8] and it only displays a low level of magnetic activity in its chromosphere. The metallicity of the star is lower than in the Sun, indicating a paucity of elements with mass greater than helium.[4] The star has 84% of the mass of the Sun and 88% of the Sun's radius. It is radiating 74%[7] of the Sun's luminosity from its photosphere at an effective temperature of 5,599 km/s.[4]
Planetary system
In 2011, an exoplanet was found in an eccentric orbit around the host star using Doppler spectroscopy. As the inclination of its orbital plane is unknown, only a lower bound on its mass can be determined. It has at least 18 times the mass of the Earth. The exoplanet is orbiting its host star with a separation of 0.25 astronomical unit|AU and a period of 50 days.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥17.98 ± 1.46 M⊕ | 0.250 ± 0.004 | 49.77 ± 0.07 | 0.31 ± 0.10 | — | — |
See also
- List of extrasolar planets
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 Gray, R. O. et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal 132 (1): 161–170. doi:10.1086/504637. Bibcode: 2006AJ....132..161G.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Mordasini, C. et al. (2011). "The HARPS search for southern extrasolar planets XXIV. Companions to HD 85390, HD 90156, and HD 103197: a Neptune analog and two intermediate-mass planets". Astronomy and Astrophysics 526: A111. doi:10.1051/0004-6361/200913521. Bibcode: 2011A&A...526A.111M.
- ↑ 5.0 5.1 Soubiran, C. et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics 616: A7. doi:10.1051/0004-6361/201832795. Bibcode: 2018A&A...616A...7S.
- ↑ 6.0 6.1 6.2 Gomes da Silva, J.; Santos, N. C.; Adibekyan, V.; Sousa, S. G.; Campante, T. L.; Figueira, P.; Bossini, D.; Delgado-Mena, E. et al. (February 2021). "Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample. I. A catalogue of homogeneous chromospheric activity". Astronomy & Astrophysics 646: A77. doi:10.1051/0004-6361/202039765. ISSN 0004-6361. Bibcode: 2021A&A...646A..77G.
- ↑ 7.0 7.1 Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics 585: 14. doi:10.1051/0004-6361/201527297. A5. Bibcode: 2016A&A...585A...5B.
- ↑ 8.0 8.1 8.2 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. doi:10.1051/0004-6361/201936523. A136. Bibcode: 2020A&A...634A.136C.
- ↑ "HD 90156". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+90156.
- ↑ Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society 450 (3): 3127–3136. doi:10.1093/mnras/stv771. Bibcode: 2015MNRAS.450.3127M.
- ↑ Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, VA: The McDonald & Woodward Publishing Company. p. 29. ISBN 978-0-939923-78-6.
Coordinates: 
10h 23m 55.2749s, −29° 38′ 43.905″
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