HD 9986

HD 9986 is a Sun-like star in the equatorial constellation of Pisces. With an apparent visual magnitude of 6.77,[2] it lies below the normal limit for visibility with the naked eye. The star is located at a distance of 83 light years from the Sun as determined from parallax measurements, but it is drifting closer with a radial velocity of −21 km/s.[1]

HD 9986

Observation data Epoch J2000      Equinox J2000
Constellation	Pisces
Right ascension	01^h 37^m 40.87927^s[1]
Declination	+12° 04′ 42.1714″[1]
Apparent magnitude (V)	6.77[2]
Characteristics
Spectral type	G5 V[3]
B−V color index	0.648±0.008[2]
Astrometry
Radial velocity (Rv)	−21.024±0.0006[1] km/s
Proper motion (μ)	RA: +120.150[1] mas/yr Dec.: +6.057[1] mas/yr
Parallax (π)	39.2718 ± 0.0405[1] mas
Distance	83.05 ± 0.09 ly (25.46 ± 0.03 pc)
Absolute magnitude (MV)	4.73[2]
Details[4]
Mass	1.02[3] M☉
Radius	1.04+0.02 −0.01[1] R☉
Luminosity	1.103±0.002[1] L☉
Surface gravity (log g)	4.43±0.01 cgs
Temperature	5,831±5 K
Metallicity [Fe/H]	+0.095±0.005 dex
Rotation	23[5] days
Rotational velocity (v sin i)	1.90±0.15 km/s
Age	3.29±0.51 Gyr
Other designations
BD+11°207, HD 9986, HIP 7585, SAO 92543[6]
Database references
SIMBAD	data

This object is a G-type main-sequence star with a stellar classification of G5 V,[3] and is a near solar twin with physical properties very similar to the Sun's. It is around 3.3[4] billion years old and is spinning slowly with a rotation period of about 23 days. A speckle survey of G-dwarfs by Elliott P. Horch in 2002 noted that HD 9986 may not be non-single star.[7]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 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.
3. Vidotto, A. A.; et al. (July 2014). "Stellar magnetism: empirical trends with age and rotation" (PDF). Monthly Notices of the Royal Astronomical Society. Cornell University - Astronomy & Astrophysics manuscript. 441 (3): 2361–2374. arXiv:1404.2733. Bibcode:2014MNRAS.441.2361V. doi:10.1093/mnras/stu728. Retrieved July 13, 2016.
4. dos Santos, Leonardo A.; et al. (August 2016). "The Solar Twin Planet Search. IV. The Sun as a typical rotator and evidence for a new rotational braking law for Sun-like stars". Astronomy & Astrophysics. 592: 8. arXiv:1606.06214. Bibcode:2016A&A...592A.156D. doi:10.1051/0004-6361/201628558. A156.
5. See, V.; Jardine, M.; Vidotto, A. A.; Donati, J. -F.; Boro Saikia, S.; Fares, R.; Folsom, C. P.; Jeffers, S. V.; Marsden, S. C.; Morin, J.; Petit, P.; BCool Collaboration (February 2018). "The open flux evolution of a solar-mass star on the main sequence". Monthly Notices of the Royal Astronomical Society. 474 (1): 536–546. arXiv:1711.03904. Bibcode:2018MNRAS.474..536S. doi:10.1093/mnras/stx2599.
6. "HD 9986". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved July 13, 2016.
7. Gray, R. O.; et al. (October 2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I". The Astronomical Journal. 126 (4): 2048–2059. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365.