| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra1 |
| Right ascension | 14h 02m 22.78173s2 |
| Declination | −27° 25′ 47.1992″2 |
| Apparent magnitude (V) | 5.471 |
| Characteristics | |
| Spectral type | K2–3III3 |
| B−V color index | 1.331±0.0031 |
| Astrometry | |
| Radial velocity (Rv) | −0.61±0.242 km/s |
| Proper motion (μ) | RA: −31.861±0.2592 mas/yr Dec.: −4.195±0.2152 mas/yr |
| Parallax (π) | 7.3651±0.1407 mas2 |
| Distance | 443 ± 8 ly (136 ± 3 pc) |
| Absolute magnitude (MV) | −0.171 |
| Details4 | |
| Mass | 1.62±0.19 M☉ |
| Radius | 21.20±2.06 R☉ |
| Luminosity | 189.6±4.22 L☉ |
| Surface gravity (log g) | 1.96±0.07 cgs |
| Temperature | 4,383±19 K |
| Metallicity [Fe/H] | −0.08±0.04 dex |
| Rotational velocity (v sin i) | 2.59±0.45 km/s |
| Age | 1.98±0.67 Gyr |
| Other designations | |
| CD−26°10060, GC 18954, HD 122430, HIP 68581, HR 5265, SAO 182182, GCRV 82475 | |
| Database references | |
| SIMBAD | data |
HD 122430 is single star6 in the equatorial constellation of Hydra. It has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude of 5.47.1 The star is located at a distance of 105.6 light years from the Sun based on parallax. It has the Bayer designation h Hydrae.7
This is an aging giant star with a stellar classification of K2–3III.3 It has completely run out of the hydrogen fuel that keeps it stable, although it is only two billion years old,4 younger than the Sun's 4.6 billion years. HD 122430 has a mass of 1.6 times and radius of 22.9 times that of the Sun.4 Despite its younger age, it has slightly lower metallicity, approximately 90%. It is radiating 1902 times the luminosity of the Sun from its photosphere at an effective temperature of 4300 K.4
A candidate exoplanet was reported orbiting the star via the radial velocity method at a conference in 2003, and designated HD 122430 b. It has an orbital period of 0.94 years and an eccentricity of 0.68.8 However, a follow-up study by Soto et al. (2015) failed to detect a signal, so it remains unconfirmed.9
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | >3.71 MJ | 1.02 | 344.95±1.08 | 0.68±0.09 | — | — |
References
References
- 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. XHIP record for this object at VizieR.
- 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.
- Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 3. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode:1982mcts.book.....H.
- Jofré, E.; et al. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931.
- "HD 117207". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-23.
- Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- Morton Wagman (2003). Lost Stars: Lost, Missing, and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas-Louis de Lacaille, John Flamsteed, and Sundry Others (2 ed.). McDonald & Woodward Publishing Company. ISBN 978-0-939923-78-6. OCLC 1131243914.
- Setiawan, J. (October 2003). Planets around evolved stars. Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets, 22–25 April 2003, Heidelberg, Germany. Vol. 539. Noordwijk, Netherlands: ESA Publications Division. pp. 595–598. Bibcode:2003ESASP.539..595S. ISBN 92-9092-849-2.
- Soto, M. G.; et al. (August 2015). "RAFT - I. Discovery of new planetary candidates and updated orbits from archival FEROS spectra". Monthly Notices of the Royal Astronomical Society. 451 (3): 3131–3144. arXiv:1505.04796. Bibcode:2015MNRAS.451.3131S. doi:10.1093/mnras/stv1144.