Zeta2 Scorpii

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ζ2 Scorpii

Reddish ζ2 Scorpii alongside the fainter ζ1 Scorpii to the south of NGC 6231
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Scorpius
Right ascension 16h 54m 35.00503s[1]
Declination −42° 21′ 40.7370″[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: −126.721 mas/yr[1]
Dec.: −228.837 mas/yr[1]
Parallax (π)24.2353 ± 0.1985 mas[1]
Distance135 ± 1 ly
(41.3 ± 0.3 pc)
Absolute magnitude (MV)0.30±0.09[6]
Details
Mass1.19±0.14[6] M
Radius21.0±1.6[6] R
Surface gravity (log g)1.84±0.10[6] cgs
Temperature4,169[6] K
Metallicity [Fe/H]+0.06[6] dex
Rotational velocity (v sin i)2.30[7] km/s
Age5.80±2.26[6] Gyr
Other designations
ζ2 Sco, Zeta2 Scorpii, Zeta2 Sco, CD−42 11646, CPD−42 7549, GC 22751, HD 152334, HIP 82729, HR 6271, LTT 6737, NLTT 43744, PPM 322371, SAO 227402.[8]
Database references
SIMBADdata

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 about 6,000 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 135 light-years 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.

References[edit]

  1. ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ a b "zet02 Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-09-20.