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Zeta2 Scorpii 
Summary
Zeta2 Scorpii (Zeta2 Sco, ζ2 Scorpii, ζ2 Sco) is a K-type orange giant star in the constellation of Scorpius.[8] It has an apparent visual magnitude which varies between 3.59 and 3.65,[2] and is located near the blue-white supergiant star ζ1 Scorpii in Earth's sky. In astronomical terms, ζ2 is much closer to the Sun and unrelated to ζ1 except for line-of sight co-incidence. ζ1 is 5,700 light-years away and probably an outlying member of open star cluster NGC 6231 (also known as the "northern jewel box" cluster), whereas ζ2 is a mere 132 lightyears distant and thus much less luminous in real terms. ζ2 can also be distinguished from its optical partner, ζ1, because of its orangish colour especially in long-exposure astrophotographs.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 54m 35.00435s[1] |
| Declination | −42° 21′ 40.7407″[1] |
| Apparent magnitude (V) | 3.59 to 3.65[2] |
| Characteristics | |
| Spectral type | K4 III[3] |
| U−B color index | +1.65[4] |
| B−V color index | +1.37[4] |
| R−I color index | +0.68[4] |
| Astrometry | |
| Radial velocity (Rv) | −18.7±0.9[5] km/s |
| Proper motion (μ) | RA: −127.72[1] mas/yr Dec.: −229.44[1] mas/yr |
| Parallax (π) | 24.65 ± 0.27 mas[1] |
| Distance | 132 ± 1 ly (40.6 ± 0.4 pc) |
| Absolute magnitude (MV) | 0.30±0.09[6] |
| Details | |
| Mass | 1.19±0.14[6] M☉ |
| Radius | 21.0±1.6[6] R☉ |
| Surface gravity (log g) | 1.84±0.10[6] cgs |
| Temperature | 4,169[6] K |
| Metallicity [Fe/H] | +0.06[6] dex |
| Rotational velocity (v sin i) | 2.30[7] km/s |
| Age | 5.80±2.26[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
References edit
- ^ a b c d e van Leeuwen, F. (November 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.
- ^ a b NSV 8028, database entry, New Catalogue of Suspected Variable Stars, the improved version, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 20, 2009.
- ^ Landi Dessy, J.; Keenan, P. C. (November 1966), "Spectral Types on the MK System for Forty-Three Bright Southern Stars, K2-M6", Astrophysical Journal, 146: 587, Bibcode:1966ApJ...146..587L, doi:10.1086/148925.
- ^ a b c HR 6271, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line November 20, 2009.
- ^ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
- ^ a b c d e f g da Silva, L.; et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics, 458 (2): 609–623, arXiv:astro-ph/0608160, Bibcode:2006A&A...458..609D, doi:10.1051/0004-6361:20065105, S2CID 9341088.
- ^ Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; de la Villarmois, E. Artur; Chavero, C.; Gómez, M.; Mauas, P. J. D. (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, S2CID 53666931, A50.
- ^ a b "zet02 Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-09-20.