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HD 47186

Coordinates: Sky map 06h 36m 08.7880s, −27° 37′ 20.268″
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HD 47186
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Canis Major
Right ascension 06h 36m 08.788s[1]
Declination −27° 37′ 20.27″[1]
Apparent magnitude (V) 7.63[2]
Characteristics
Evolutionary stage main sequence
Spectral type G6V[3]
B−V color index 0.714±0.002[2]
Astrometry
Radial velocity (Rv)4.238±0.0003[4] km/s
Proper motion (μ) RA: 21.582 mas/yr[1]
Dec.: −262.843 mas/yr[1]
Parallax (π)26.7476 ± 0.0217 mas[1]
Distance121.94 ± 0.10 ly
(37.39 ± 0.03 pc)
Absolute magnitude (MV)4.64[2]
Details
Mass1.05±0.01[5] M
Radius1.12±0.01[5] R
Luminosity1.219±0.005[5] L
Surface gravity (log g)4.35±0.01[5] cgs
Temperature5,736±21[5] K
Metallicity [Fe/H]0.23[6] dex
Rotational velocity (v sin i)1.953[6] km/s
Age5.5±0.6[5] Gyr
Other designations
CD−27° 3124, HD 47186, HIP 31540, SAO 172008, LTT 2597, NLTT 16742[7]
Database references
SIMBADdata
Exoplanet Archivedata

HD 47186 is a star with a pair of orbiting exoplanets in the southern constellation of Canis Major. The system is located at a distance of 122 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 4.2 km/s.[4] Although it has an absolute magnitude of 4.64,[2] at the distance of this system the apparent visual magnitude is 7.63;[2] too faint to be seen with the naked eye. It has a high proper motion, traversing the celestial sphere at an angular rate of 0.272·yr−1.[8]

The spectrum of HD 47186 matches a G-type main-sequence star with a stellar classification of G6V.[3] It is an estimated 5.5[5] billion years old and is spinning with a projected rotational velocity of 2 km/s.[6] The star has 5% greater mass and a 12% larger girth compared to the Sun.[5] The abundance of iron, a measure of the star's metallicity, is 1.7 times more than the Sun, making it metal-rich.[6] HD 47186 is radiating 1.2 times the luminosity of the Sun from its photosphere at an effective temperature of 5,736 K.[5]

Planetary system

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Announced in June 2008, two extrasolar planets were discovered orbiting the star. Both planets are less massive than Jupiter. The inner planet HD 47186 b orbits close to the star and is termed a “hot Neptune”. The outer planet HD 47186 c orbits in a similar distance from the star as the asteroid Vesta, at around 2.4 AU. The inner planet orbits in a circular path while the outer planet orbits in an eccentric path.[9]

The HD 47186 planetary system[9]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥0.07167 MJ 0.050 4.0845 ± 0.0002 0.038 ± 0.020
c ≥0.35061 MJ 2.395 1353.6 ± 57.1 0.249 ± 0.073

See also

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References

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  1. ^ 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.
  2. ^ a b c d e 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.
  3. ^ a b Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
  4. ^ a b Soubiran, C.; et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics. 616: A7. arXiv:1804.09370. Bibcode:2018A&A...616A...7S. doi:10.1051/0004-6361/201832795. S2CID 52952408.
  5. ^ a b c d e f g h i 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.
  6. ^ a b c d Costa Silva, A. R.; et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics. 634: 10. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. S2CID 209405391. A136.
  7. ^ "HD 47186". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-23.
  8. ^ Wroblewski, H.; Torres, C. (March 1998), "New proper motion determination of Luyten catalogue stars (LTT) with declination between -5° and -30° and right ascension between 0h and 13h 30m", Astronomy and Astrophysics Supplement, 128: 457–458, Bibcode:1998A&AS..128..457W, doi:10.1051/aas:1998157
  9. ^ a b Bouchy, François; et al. (2009). "The HARPS Search for Southern Extra-solar Planets. XVII. Super-Earth and Neptune-mass Planets in Multiple Planet Systems HD 47186 and HD 181433". Astronomy and Astrophysics. 496 (2): 527–31. arXiv:0812.1608. Bibcode:2009A&A...496..527B. doi:10.1051/0004-6361:200810669. S2CID 117778593.

Further reading

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