49 Cassiopeiae

49 Cassiopeiae is a binary star[8] system in the northern circumpolar constellation of Cassiopeia. It is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of 5.22.[2] The system is located about 412 light years away from the Sun, based on parallax. The pair had an angular separation of 5.40″ along a position angle of 244°, as of 2008, with the brighter component being of magnitude 5.32 and its faint companion having magnitude 12.30.[3]

49 Cassiopeiae

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cassiopeia
Right ascension	02^h 05^m 31.54793^s[1]
Declination	+76° 06′ 54.2148″[1]
Apparent magnitude (V)	5.22[2] (5.32 + 12.30)[3]
Characteristics
Evolutionary stage	horizontal branch
Spectral type	G8III[4] + ?
B−V color index	0.954±0.003[2]
Astrometry
49 Cas A
Radial velocity (Rv)	−0.20±0.30[2] km/s
Proper motion (μ)	RA: −11.303[1] mas/yr Dec.: −20.459[1] mas/yr
Parallax (π)	7.9161 ± 0.0981[1] mas
Distance	412 ± 5 ly (126 ± 2 pc)
Absolute magnitude (MV)	−0.44[5]
49 Cas B
Proper motion (μ)	RA: −13.385[6] mas/yr Dec.: −19.193[6] mas/yr
Parallax (π)	7.8058 ± 0.0305[6] mas
Distance	418 ± 2 ly (128.1 ± 0.5 pc)
Details
49 Cas A
Mass	3.19[5] M☉
Radius	16.14+0.30 −0.43[1] R☉
Luminosity	141.604±2.13[1] L☉
Surface gravity (log g)	2.52[5] cgs
Temperature	4,956.5+67.5 −46.5[1] K
Metallicity [Fe/H]	−0.03[5] dex
Age	302[5] Myr
49 Cas B
Radius	0.66[6] R☉
Luminosity	0.281[6] L☉
Temperature	5,163[6] K
Other designations
49 Cas, BD+75°86, GC 2475, HD 12339, HIP 9763, HR 592, SAO 4565, CCDM J02056+7607, GSC 04495-01881[7]
Database references
SIMBAD	data

The primary, designated component A,[3] is an aging giant star with a stellar classification of G8III.[4] It is 302 million years old with 3.3 times the mass of the Sun.[5] With the supply of hydrogen at its core exhausted, the star has now expanded to 16[1] times the Sun's radius. It is a red clump giant on the horizontal branch, which indicates it is generating energy through the fusion of helium at its core.[9] The star is radiating 142[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,957 K.[1] Its faint secondary companion, component B, is of an unknown spectral type.

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, S2CID 119257644.
3. Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
4. Abt, Helmut A. (2008), "Visual Multiples. IX. MK Spectral Types", The Astrophysical Journal Supplement Series, 176 (1): 216–217, Bibcode:2008ApJS..176..216A, doi:10.1086/525529.
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, S2CID 16258166.
6. 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.
7. "49 Cas". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-22.
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. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.