20 Camelopardalis

20 Camelopardalis (20 Cam) is a solitary star in the circumpolar constellation Camelopardalis. It has an apparent magnitude of 7.45, making it readily visible in binoculars but not to the naked eye. Located about 880 light years away, it is approaching the Solar System with a radial velocity of −50.3 km/s. Due to its faintness, 20 Cam is one of the 220 Flamsteed stars without Bright Star Catalog designations.^[10]

20 Camelopardalis

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Camelopardalis
Right ascension	05h 37m 27.0446s[1]
Declination	+56° 29′ 16.086″[1]
Apparent magnitude (V)	7.45±0.01[2]
Characteristics
Evolutionary stage	horizontal branch[3]
Spectral type	G8 II-III[4]
U−B color index	+0.69[2]
B−V color index	+0.98[2]
Astrometry
Radial velocity (Rv)	−50.3±2.3[5] km/s
Proper motion (μ)	RA: −0.534 mas/yr[1] Dec.: −7.186 mas/yr[1]
Parallax (π)	3.7078 ± 0.1769 mas[1]
Distance	880 ± 40 ly (270 ± 10 pc)
Absolute magnitude (MV)	+1.39[6]
Details
Mass	1.83[7] M☉
Radius	12.54[8] R☉
Luminosity	142[5] L☉
Surface gravity (log g)	2.79[9] cgs
Temperature	5,064[9] K
Metallicity [Fe/H]	−0.03[9] dex
Other designations
20 Cam, AG+56°533, BD+56°1041, GC 6947, HD 36770, HIP 26426, SAO 25277
Database references
SIMBAD	data

20 Cam is a red clump^[3] giant star with a spectral classification of G8 II-III.^[4] It has a measured angular diameter of 0.44 mas,^[11] with an actual radius of 13 R_☉ at its estimated distance. It has 1.83 times the mass of the Sun and shines at 142 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 5,064 K, giving it a yellow glow. 20 Cam's metallicity – elements heavier than helium – is around solar level.^[9]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89: 415. Bibcode:1991A&AS...89..415O. ISSN 0365-0138.
3. Rybka, S. P. (2007). "A catalogue of candidate Red Clump stars in the Tycho-2". Kinematika I Fizika Nebesnykh Tel. 23: 102. Bibcode:2007KFNT...23..102R. ISSN 0233-7665.
4. Yoss, Kenneth M. (November 1961). "Spectral and Luminosity Classifications and Measurements of the Strength of Cyanogen Absorption for Late-Type Stars from Objective-Prism Spectra". The Astrophysical Journal. 134: 809. Bibcode:1961ApJ...134..809Y. doi:10.1086/147209. ISSN 0004-637X.
5. 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.
6. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 119257644.
7. Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy & Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. ISSN 0004-6361.
8. Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. S2CID 237605138.
9. Ting, Yuan-Sen; Hawkins, Keith; Rix, Hans-Walter (3 May 2018). "A Large and Pristine Sample of Standard Candles across the Milky Way: ~100,000 Red Clump Stars with 3% Contamination". The Astrophysical Journal. 858 (1): L7. arXiv:1803.06650. Bibcode:2018ApJ...858L...7T. doi:10.3847/2041-8213/aabf8e. ISSN 0004-637X.
10. Bidelman, W. P. (1990). "Flamsteed stars not contained in the Yale "Catalogue of Bright Stars"". Bulletin d'Information du Centre de Données Stellaires. 38: 13. Bibcode:1990BICDS..38...13B.
11. Bourgés, L.; Lafrasse, S.; Mella, G.; Chesneau, O.; Bouquin, J. L.; Duvert, G.; Chelli, A.; Delfosse, X. (May 2014). "The JMMC Stellar Diameters Catalog v2 (JSDC): A New Release Based on SearchCal Improvements". Astronomical Data Analysis Software and Systems Xxiii. 485: 223. Bibcode:2014ASPC..485..223B.