Astronomy:HD 9446
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 01h 33m 20.1848s[1] |
| Declination | +29° 15′ 54.5390″[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: 190.249±0.140[1] mas/yr Dec.: −53.650±0.201[1] mas/yr |
| Parallax (π) | 19.8336 ± 0.1376[1] mas |
| Distance | 164 ± 1 ly (50.4 ± 0.3 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 |
| Extrasolar Planets Encyclopaedia | 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 | — | — |
See also
- List of extrasolar planets
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 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. doi:10.1051/0004-6361/200913790. Bibcode: 2010A&A...513A..69H. http://www.aanda.org/articles/aa/full_html/2010/05/aa13790-09/aa13790-09.html.
- ↑ Bonfanti, A. et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics 575: A18. doi:10.1051/0004-6361/201424951. Bibcode: 2015A&A...575A..18B. http://www.aanda.org/articles/aa/full_html/2015/03/aa24951-14/aa24951-14.html.
- ↑ "HD 9446". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+9446.
- ↑ 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, doi:10.1051/0004-6361/201014741, Bibcode: 2010A&A...522A..98M, https://zenodo.org/record/998268
- ↑ Hill, Michelle L.; Mocnik, Teo; Kane, Stephen R.; Henry, Gregory W.; Pepper, Joshua; Hinkel, Natalie R.; Dalba, Paul A.; Fulton, Benjamin J. et al. (2020). "Orbital Refinement and Stellar Properties for the HD 9446, HD 43691, and HD 179079 Planetary Systems". The Astronomical Journal 159 (5): 197. doi:10.3847/1538-3881/ab7d33. Bibcode: 2020AJ....159..197H.
Coordinates: 
01h 33m 20s, +29° 15′ 55″
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