HD 43691

HD 43691

Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	06^h 19^m 34.676^s[1]
Declination	+41° 05′ 32.30″[1]
Apparent magnitude (V)	8.03[2]
Characteristics
Spectral type	G0 IV[3]
B−V color index	0.596±0.015[2]
Variable type	None[4]
Astrometry
Radial velocity (Rv)	−28.97±0.02[2] km/s
Proper motion (μ)	RA: 22.684 mas/yr[1] Dec.: −53.140 mas/yr[1]
Parallax (π)	11.6726 ± 0.0346 mas[1]
Distance	279.4 ± 0.8 ly (85.7 ± 0.3 pc)
Absolute magnitude (MV)	3.52[2]
Details
Mass	1.32±0.09[4] M☉
Radius	1.704±0.023[4] R☉
Luminosity	2.24±0.02[5] L☉
Surface gravity (log g)	4.19±0.02[5] cgs
Temperature	5,920±34[5] K
Metallicity [Fe/H]	0.32±0.03[4] dex
Rotational velocity (v sin i)	4.7[3] km/s
Age	3.1±2.5[5] Gyr
Other designations
BD+41° 1415, HD 43691, HIP 30057, SAO 41025, PPM 48960, TYC 2930-2105-1, GSC 02930-02105, 2MASS J06193467+4105321[6]
Database references
SIMBAD	data

HD 43691 is a star with an orbiting exoplanet in the constellation Auriga. With an apparent visual magnitude of 8.03,^[2] it is too faint to be visible to the naked eye. This system is located at a distance of 279 light years based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −29 km/s.^[2]

This is a slightly evolved G-type subgiant star with a stellar classification of G0 IV.^[3] It is ceasing thermonuclear fusion of hydrogen in its core and will expand to become a red giant. The star has 32% greater mass than the Sun and has a 70% larger girth.^[4] It is radiating 2.2 times the luminosity of the Sun from its photosphere at an effective temperature of 5,920 K.^[5] The level of chromospheric activity is minimal, allowing for accurate measurement of radial velocity variation.^[3]

Planetary system

In July 2007, the star is found to have a super-jovian exoplanet in orbit around it.^[3] It has minimum mass two and a half times that of Jupiter and orbits the star closer than Mercury to the Sun.

The HD 43691 planetary system^[7]^[4]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥2.57+0.31 −0.34 MJ	0.238+0.014 −0.016	36.99913+0.00095 −0.00092	0.085+0.012 −0.011	—	—

See also

• List of extrasolar planets

References

1. 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. 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. da Silva, Ronaldo; et al. (October 2007). "ELODIE metallicity-biased search for transiting Hot Jupiters IV. Intermediate period planets orbiting the stars HD 43691 and HD 132406". Astronomy and Astrophysics. 473 (1): 323–328. arXiv:0707.0958. Bibcode:2007A&A...473..323D. doi:10.1051/0004-6361:20077314. S2CID 18805775.
4. Hill, Michelle L.; 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. arXiv:2003.02385. Bibcode:2020AJ....159..197H. doi:10.3847/1538-3881/ab7d33. S2CID 212414679.
5. 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. "HD 43691". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-12-16.
7. Ment, Kristo; et al. (2018). "Radial Velocities from the N2K Project: Six New Cold Gas Giant Planets Orbiting HD 55696, HD 98736, HD 148164, HD 203473, and HD 211810". The Astronomical Journal. 156 (5). 213. arXiv:1809.01228. Bibcode:2018AJ....156..213M. doi:10.3847/1538-3881/aae1f5. S2CID 119243619.