HD 47186

HD 47186
Observation data
Epoch J2000.0      Equinox ICRS
Constellation Canis Major
Right ascension 06h 36m 08.788s
Declination −27° 37′ 20.27″
Apparent magnitude (V) 7.63
Characteristics
Evolutionary stage main sequence
Spectral type G6V
B−V color index 0.714±0.002
Astrometry
Radial velocity (Rv)4.238±0.0003 km/s
Proper motion (μ) RA: 21.582 mas/yr
Dec.: −262.843 mas/yr
Parallax (π)26.7476±0.0217 mas
Distance121.94 ± 0.10 ly
(37.39 ± 0.03 pc)
Absolute magnitude (MV)4.64
Details
Mass1.05±0.01 M☉
Radius1.12±0.01 R☉
Luminosity1.219±0.005 L☉
Surface gravity (log g)4.35±0.01 cgs
Temperature5,736±21 K
Metallicity [Fe/H]0.23 dex
Rotational velocity (v sin i)1.953 km/s
Age5.5±0.6 Gyr
Other designations
CD−27°3124, HD 47186, HIP 31540, SAO 172008, LTT 2597, NLTT 16742
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. Although it has an absolute magnitude of 4.64, at the distance of this system the apparent visual magnitude is 7.63; 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.

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

Planetary system

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 in the Solar System, at around 2.4 AU. The inner planet orbits in a circular path while the outer planet orbits in an eccentric path.

The HD 47186 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination
(°)		 Radius
b ≥22.8 M🜨 0.050 4.0845 ± 0.0002 0.038 ± 0.020 — —
c ≥111.46 M🜨 2.395 1353.6 ± 57.1 0.249 ± 0.073 — —

See also

References

  1. 1 2 3 4 5 6 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. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 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.
  3. 1 2 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. 1 2 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. 1 2 3 4 5 6 7 8 9 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. 1 2 3 4 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. 1 2 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