HD 9446
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 01h 33m 20.18561s[1] |
| Declination | +29° 15′ 54.5375″[1] |
| Apparent magnitude (V) | 8.35[2] |
| Characteristics | |
| Spectral type | G5V[3] |
| U−B color index | +0.14[2] |
| B−V color index | +0.68[2] |
| Astrometry | |
| Radial velocity (Rv) | 20.2[4] km/s |
| Proper motion (μ) | RA: 192.01[1] mas/yr Dec.: –53.99[1] mas/yr |
| Parallax (π) | 19.10 ± 1.06[1] mas |
| Distance | 171 ± 9 ly (52 ± 3 pc) |
| Details | |
| Mass | 1.00 ± 0.10[3] M☉ |
| Radius | 1.00[3] R☉ |
| Luminosity | 1.1[3] L☉ |
| Surface gravity (log g) | 4.53 ± 0.16[3] cgs |
| Temperature | 5793 ± 22[3] K |
| Metallicity [Fe/H] | 0.09 ± 0.05[3] dex |
| Rotational velocity (v sin i) | 4 ± 1[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
HD 9446 is a star located about 171 light-years away in the constellation of Triangulum. It is a G-type main sequence star with a stellar classification of G5V. The physical properties this star appear similar to the Sun, making it a candidate solar twin. However, the measured abundance of elements with more mass than helium is above the accepted range.[5] The amount of activity measured in the chromosphere corresponds to a star with a rotation period of about 10 days.[3]
Planetary system
On 5 January 2010, scientists announced the discovery of two planets orbiting around HD 9446.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.70 ± 0.06 MJ | 0.189 ± 0.006 | 30.052 ± 0.027 | 0.20 ± 0.06 | — | — |
| c | ≥ 1.82 ± 0.17 MJ | 0.654 ± 0.022 | 192.9 ± 0.9 | 0.06 ± 0.06 | — | — |
See also
References
- 1 2 3 4 5 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- 1 2 3 "LTT 10545 -- High proper-motion Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2011-12-13.
- 1 2 3 4 5 6 7 8 9 10 11 Hébrard, G.; et al. (2010). "The SOPHIE search for northern extrasolar planets: II. A multi-planet system around HD 9446". Astronomy & Astrophysics 513. arXiv:1001.0682. Bibcode:2010A&A...513A..69H. doi:10.1051/0004-6361/200913790.
- ↑ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institution of Washington. Bibcode:1953QB901.W495.....
- ↑ 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, arXiv:1007.5351, Bibcode:2010A&A...522A..98M, doi:10.1051/0004-6361/201014741
Coordinates: 
01h 33m 20s, +29° 15′ 55″
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