Xi2 Capricorni

Xi² Capricorni (ξ² Capricorni) is a yellow-white hued star in the southern constellation of Capricornus. It is dimly visible to the naked eye on a dark night, having an apparent visual magnitude of +5.83.^[2] Based upon an annual parallax shift of 36.10 mas as seen from Earth,^[1] this system is located 90 light years from the Sun.

For other stars with this Bayer designation, see ξ Capricorni.

Xi² Capricorni

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Capricornus
Right ascension	20h 12m 25.87020s[1]
Declination	−12° 37′ 02.9967″[1]
Apparent magnitude (V)	+5.83[2]
Characteristics
Spectral type	F7 V Fe−0.5[3]
B−V color index	+0.46[2]
Astrometry
Radial velocity (Rv)	+27.1[4] km/s
Proper motion (μ)	RA: +192.35[1] mas/yr Dec.: −196.20[1] mas/yr
Parallax (π)	36.10 ± 0.41 mas[1]
Distance	90 ± 1 ly (27.7 ± 0.3 pc)
Absolute magnitude (MV)	3.64±0.02[5]
Details[6]
Mass	1.20+0.01 −0.02 M☉
Surface gravity (log g)	4.25±0.03 cgs
Temperature	6,411±63 K
Metallicity [Fe/H]	−0.25±0.05 dex
Rotational velocity (v sin i)	11[2] km/s
Age	3.04+0.45 −0.51 Gyr
Other designations
ξ2 Cap, 2 Cap, BD−13° 5608, GC 28035, GJ 4139, HD 191862, HIP 99572, HR 7715, SAO 163337, CCDM J20124-1237, WDS J20124-1237A[7]
Database references
SIMBAD	data

This is an F-type main-sequence star with a stellar classification of F7 V Fe−0.5,^[3] where the suffix notation indicates the spectrum displays a mild underabundance of iron. It is around three billion years old with 1.2 times the mass of the Sun.^[6] Although considered a single star,^[8] there is reason to suspect it forms a wide physical pair with the visual magnitude 10.94^[9] red dwarf star LP 754–50.^[10] They have a projected separation of (28.3±0.3)×10³ AU, with LP 754–50 having an estimated 0.55 times the mass of the Sun. If they are gravitationally bound, their orbital period would be around 3.7 million years.^[10]

References

1. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
2. Mizusawa, Trisha F.; et al. (November 2012), "Exploring the Effects of Stellar Rotation and Wind Clearing: Debris Disks around F Stars", The Astronomical Journal, 144 (5): 16, arXiv:1208.6248, Bibcode:2012AJ....144..135M, doi:10.1088/0004-6256/144/5/135, S2CID 41406330, 135.
3. Gray, R. O.; et al. (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. Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14,000 F and G dwarfs", Astronomy and Astrophysics, 418: 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959, S2CID 11027621.
5. Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
6. Ramírez, I.; et al. (September 2012), "Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets", The Astrophysical Journal, 756 (1): 46, arXiv:1207.0499, Bibcode:2012ApJ...756...46R, doi:10.1088/0004-637X/756/1/46, S2CID 119199829.
7. "ksi Cap". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-31.
8. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
9. "LP 754-50". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-31.
10. Caballero, J. A. (November 2009), "Reaching the boundary between stellar kinematic groups and very wide binaries. The Washington double stars with the widest angular separations", Astronomy and Astrophysics, 507 (1): 251–259, arXiv:0908.2761, Bibcode:2009A&A...507..251C, doi:10.1051/0004-6361/200912596, S2CID 118194112.