HD 9446
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 01h 33m 20.1847s[1] |
| Declination | +29° 15′ 54.539″[1] |
| Apparent magnitude (V) | 8.35[2] |
| Characteristics | |
| Spectral type | G5V[3] |
| B−V color index | +0.680±0.015[2] |
| Astrometry | |
| Radial velocity (Rv) | +21.2±3.1[2] km/s |
| Proper motion (μ) | RA: 190.343(28) mas/yr Dec.: −53.675(31) mas/yr |
| Parallax (π) | 19.9200 ± 0.0413 mas[1] |
| Distance | 163.7 ± 0.3 ly (50.2 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.76[2] |
| Details | |
| Mass | 1.07±0.18 [4] M☉ |
| Radius | 0.984±0.01 [4] R☉ |
| Luminosity | 1.1[3] L☉ |
| Surface gravity (log g) | 4.53±0.16[3] cgs |
| Temperature | 5,793±22[3] K |
| Metallicity [Fe/H] | 0.09±0.05[3] dex |
| Rotational velocity (v sin i) | 4±1 km/s |
| Age | 2.0±1.5[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 9446 is a star located about 164[1] light-years away in the constellation of Triangulum, near the southwestern constellation border with Pisces. This object can be viewed with binoculars or a telescope, but it is too faint to be seen with the naked eye at its apparent visual magnitude of 8.35.[2] It is drifting further away from the Sun with a radial velocity of +21 km/s.[2]
This object is a G-type main sequence star with a stellar classification of G5V.[3] The physical properties this star appear similar to the Sun, making it a candidate solar analog. However, the measured abundance of elements with more mass than helium is outside the accepted range.[7] It is roughly two billion years in age and has an active chromosphere. The amount of activity measured in the chromosphere corresponds to a star with a rotation period of about 10 days.[3]
On 5 January 2010, scientists announced the discovery of two planets orbiting around HD 9446.[3] In addition, another exoplanet candidate is detected by astrometry in 2024.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.687±0.0056 MJ | 0.1892±0.0065 | 30.0608+0.0034 −0.0033 |
0.20±0.06 | — | — |
| c | ≥ 1.71±0.13 MJ | 0.646±0.022 | 189.6±0.13 | 0.06±0.06 | — | — |
| d (unconfirmed) | 1.5 MJ | 7.0 | — | — | — | — |
See also
[edit]References
[edit]- ^ a b c d 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 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 g h i Hébrard, Guillaume; Bonfils, Xavier; Ségransan, Damien; Moutou, Claire; Delfosse, Xavier; Bouchy, François; Boisse, Isabelle; Arnold, Luc (2010). "The SOPHIE Search for Northern Extrasolar Planets: II. A Multi-planet System Around HD 9446". Astronomy & Astrophysics. 513: A69. arXiv:1001.0682. Bibcode:2010A&A...513A..69H. doi:10.1051/0004-6361/200913790. S2CID 119306916.
- ^ a b c Hill, Michelle L.; Mocnik, Teo; Kane, Stephen R.; Henry, Gregory W.; Pepper, Joshua; Hinkel, Natalie R.; Dalba, Paul A.; Fulton, Benjamin J.; Stassun, Keivan G.; Rosenthal, Lee J.; Howard, Andrew W.; Howell, Steve B.; Everett, Mark E.; Boyajian, Tabetha S.; Fischer, Debra A. (2020-05-01). "Orbital Refinement and Stellar Properties for the HD 9446, HD 43691, and HD 179079 Planetary Systems". The Astronomical Journal. 159 (5): 197. arXiv:2003.02385. doi:10.3847/1538-3881/ab7d33. ISSN 0004-6256.
- ^ Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. S2CID 54555839.
- ^ "HD 9446". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-10.
- ^ Meléndez, J.; et al. (November 2010), "uvby-β photometry of solar twins. The solar colors, model atmospheres, and the Teff and metallicity scales", Astronomy and Astrophysics, 522: A98, arXiv:1007.5351, Bibcode:2010A&A...522A..98M, doi:10.1051/0004-6361/201014741, S2CID 118481647
- ^ a b Kiefer, Flavien; Lagrange, Anne-Marie; Rubini, Pascal; Philipot, Florian (2024). "Searching for substellar companion candidates with Gaia. II. A catalog of 9,698 planet candidate solar-type hosts". Astronomy and Astrophysics. arXiv:2409.16993. doi:10.1051/0004-6361/202451745.
