Chi Cassiopeiae

Chi Cassiopeiae (χ Cassiopeiae) is a solitary,[8] yellow-hued star in the constellation Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of +4.7.[2] Based upon an annual parallax shift of 15.67 mas as seen from Earth,[1] this system is located roughly 208 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.18 due to interstellar dust.[4]

Chi Cassiopeiae

Map of the Bayer-designated stars in Cassiopeia. Chi Cassiopeiae is circled.
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Cassiopeia
Right ascension	01^h 25^m 56.02238^s[1]
Declination	+68° 07′ 48.0460″[1]
Apparent magnitude (V)	+4.696[2]
Characteristics
Spectral type	G9 IIIb[3]
U−B color index	+0.762[2]
B−V color index	+0.997[2]
Astrometry
Radial velocity (Rv)	+6.66±0.14[4] km/s
Proper motion (μ)	RA: −43.03±0.34[1] mas/yr Dec.: −22.31±0.32[1] mas/yr
Parallax (π)	15.67 ± 0.39[1] mas
Distance	208 ± 5 ly (64 ± 2 pc)
Absolute magnitude (MV)	+0.52[5]
Details[5]
Mass	2.04 M☉
Radius	11.0±0.8[3] R☉
Luminosity	67.6 L☉
Surface gravity (log g)	2.21 cgs
Temperature	4,746 K
Metallicity [Fe/H]	−0.34 dex
Rotational velocity (v sin i)	0.44±0.45[6] km/s
Age	1.0 Gyr
Other designations
χ Cas, 39 Cas, BD+58° 260, HD 9408, HIP 7294, HR 442, SAO 22397[7]
Database references
SIMBAD	data

χ Cassiopeiae in optical light

With a stellar classification of G9 IIIb,[3] it has the spectrum of an evolved, G-type giant star. It has an estimated age of a billion years[5] and is a red clump star that it is generating energy through helium fusion at its core.[9] The star has about double[5] the mass of the Sun and has expanded to 11[3] times the Sun's radius. It is radiating 67.6 times the Sun's luminosity from its photosphere at an effective temperature of 4,746 K.[5]

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.
2. Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society, 172 (3): 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
3. Nordgren, Tyler E.; et al. (December 1999), "Stellar Angular Diameters of Late-Type Giants and Supergiants Measured with the Navy Prototype Optical Interferometer", The Astronomical Journal, 118 (6): 3032–3038, Bibcode:1999AJ....118.3032N, doi:10.1086/301114.
4. Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430: 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272.
5. Takeda, Yoichi; et al. (August 2008), "Stellar Parameters and Elemental Abundances of Late-G Giants", Publications of the Astronomical Society of Japan, 60 (4): 781–802, arXiv:0805.2434, Bibcode:2008PASJ...60..781T, doi:10.1093/pasj/60.4.781.
6. Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474.
7. "chi Cas". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-30.
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.
9. Valentini, M.; Munari, U. (November 2010), "A spectroscopic survey of faint, high-Galactic-latitude red clump stars. I. The high resolution sample", Astronomy and Astrophysics, 522: A79, arXiv:1007.0207, Bibcode:2010A&A...522A..79V, doi:10.1051/0004-6361/201014870.