| 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 [3] | |
| Mass | 1.00±0.10 M☉ |
| Radius | 1.00 R☉ |
| Luminosity | 1.1 L☉ |
| Surface gravity (log g) | 4.53±0.16 cgs |
| Temperature | 5,793±22 K |
| Metallicity [Fe/H] | 0.09±0.05 dex |
| Rotational velocity (v sin i) | 4±1 km/s |
| Age | 2.0±1.5 [4] 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. [6] 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]
| 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 | — | — |
- ^ 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 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.
- ^ 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
- ^ 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.; Rodriguez, Joseph E.; Beatty, Thomas G.; James, David J. (2020). "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. Bibcode: 2020AJ....159..197H. doi: 10.3847/1538-3881/ab7d33. S2CID 212414679.
| 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 [3] | |
| Mass | 1.00±0.10 M☉ |
| Radius | 1.00 R☉ |
| Luminosity | 1.1 L☉ |
| Surface gravity (log g) | 4.53±0.16 cgs |
| Temperature | 5,793±22 K |
| Metallicity [Fe/H] | 0.09±0.05 dex |
| Rotational velocity (v sin i) | 4±1 km/s |
| Age | 2.0±1.5 [4] 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. [6] 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]
| 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 | — | — |
- ^ 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 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.
- ^ 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
- ^ 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.; Rodriguez, Joseph E.; Beatty, Thomas G.; James, David J. (2020). "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. Bibcode: 2020AJ....159..197H. doi: 10.3847/1538-3881/ab7d33. S2CID 212414679.