HD 9446

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
Distance171 ± 9 ly
(52 ± 3 pc)
Details
Mass1.00 ± 0.10[3] M
Radius1.00[3] R
Luminosity1.1[3] L
Surface gravity (log g)4.53 ± 0.16[3] cgs
Temperature5793 ± 22[3] K
Metallicity [Fe/H]0.09 ± 0.05[3] dex
Rotational velocity (v sin i)4 ± 1[3] km/s
Age2.0 ± 1.5[5] Gyr
Other designations
BD+28 253, HIP 7245, HD 9446, SAO 74788.
Database references
SIMBADdata
Exoplanet Archivedata
Extrasolar Planets
Encyclopaedia
data

HD 9446 is a star located about 172.8 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 as a solar analog. However, the measured abundance of elements with more mass than helium is above the accepted range.[6] The amount of activity measured in the chromosphere corresponds to a star with a rotation period of about 10 days.[3]

Sun comparison

This chart compares the sun to HD 9446.

Identifier J2000 Coordinates Distance
(ly)
Stellar
Class
Temperature
(K)
Metallicity
(dex)
Age
(Gyr)
Notes
Right ascension Declination
Sun 0.00 G2V 5,778 +0.00 4.6 [7]
HD 9446 [8] 01h 33m 20.18s +29° 15 54.53 172.8 G5V 5793 0.09

Planetary system

On 5 January 2010, scientists announced the discovery of two planets orbiting around HD 9446.[3]

The HD 9446 planetary system[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. 1 2 3 4 5 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. 1 2 3 "LTT 10545 -- High proper-motion Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2011-12-13.
  3. 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:1001.0682Freely accessible. Bibcode:2010A&A...513A..69H. doi:10.1051/0004-6361/200913790.
  4. Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
  5. Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302Freely accessible. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
  6. 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:1007.5351Freely accessible, Bibcode:2010A&A...522A..98M, doi:10.1051/0004-6361/201014741
  7. Williams, D.R. (2004). "Sun Fact Sheet". NASA. Retrieved 2009-06-23.
  8. HD 9446 at SIMBAD - Ids - Bibliography - Image.

Coordinates: 01h 33m 20s, +29° 15′ 55″


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