HD 120213

HD 120213

Observation data Epoch J2000      Equinox J2000
Constellation	Chamaeleon
Right ascension	13^h 55^m 38.8756^s[1]
Declination	−82° 39′ 58.2871″[1]
Apparent magnitude (V)	5.94[2]
Characteristics
Spectral type	K2 III: CN−1 CH −2.5[3]
U−B color index	+1.59[2]
B−V color index	+1.45[2]
Astrometry
Radial velocity (Rv)	−35.2±0.6[4] km/s
Proper motion (μ)	RA: −24.805 mas/yr[1] Dec.: −23.580 mas/yr[1]
Parallax (π)	3.585 ± 0.0375 mas[1]
Distance	910 ± 10 ly (279 ± 3 pc)
Absolute magnitude (MV)	−0.98[5]
Details
Mass	4.2^+1.2 −0.7[6] M☉
Radius	38.6^+7.5 −5.1[7] R☉
Luminosity	503±13[7] L☉
Surface gravity (log g)	1.95±0.26[6] cgs
Temperature	4,401^+327 −376[7] K
Metallicity [Fe/H]	−0.25±0.10[6] dex
Rotational velocity (v sin i)	<1[8] km/s
Other designations
50 G. Chamaeleontis, CPD−82°585, GC 18731, HD 120213, HIP 68009, HR 5188, SAO 258683[9][10]
Database references
SIMBAD	data

HD 120213 (HR 5188) is a solitary star in the southern circumpolar constellation Chamaeleon. It is faintly visible to the naked eye with an apparent magnitude of 5.94 and is estimated to be 910 light years away from the Solar System. However, the object is drifting closer with a heliocentric radial velocity of −35 km/s.

HD 120213 has a stellar classification of K2 III: CN−1 CH −2.5,^[3] indicating that its a red giant with an under abundance of CH molecules and cyano radicals in its spectrum. It has also been classified as a mild barium star,^[11] but there is uncertainty about the spectral class. It has 4.2 times the mass of the Sun^[6] and an enlarged radii of 38.6 R_☉.^[7] It shines at 503 times the luminosity of the Sun from its photosphere at an effective temperature of 4,401 K,^[7] giving it an orange hue. HD 120213 has a metallicity 56% that of the Sun^[6] and spins with a projected rotational velocity too low to be accurately measured.^[8]

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. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
3. Keenan, Philip C.; McNeil, Raymond C. (October 1989). "The Perkins catalog of revised MK types for the cooler stars". The Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. eISSN 1538-4365. ISSN 0067-0049.
4. Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. ISSN 1063-7737. S2CID 119231169.
5. 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 255204555.
6. Palacios, A.; Jasniewicz, G.; Masseron, T.; Thévenin, F.; Itam-Pasquet, J.; Parthasarathy, M. (16 February 2016). "New determination of abundances and stellar parameters for a set of weakG-band stars". Astronomy & Astrophysics. 587: A42. arXiv:1512.04417. Bibcode:2016A&A...587A..42P. doi:10.1051/0004-6361/201526566. eISSN 1432-0746. ISSN 0004-6361.
7. 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.
8. De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars: V. Southern stars⋆⋆⋆". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361.
9. "HD 120213". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 6 June 2022.
10. Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
11. Lu, Phillip K. (June 1991). "Taxonomy of barium stars". The Astronomical Journal. 101: 2229. Bibcode:1991AJ....101.2229L. doi:10.1086/115845. ISSN 0004-6256.