Zeta Cephei
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 10m 51.279s[1] |
| Declination | +58° 12′ 04.53″[1] |
| Apparent magnitude (V) | 3.35[2] |
| Characteristics | |
| Spectral type | K1.5 Ib[3] |
| B−V color index | +1.55[2] |
| Variable type | Eclipsing binary?[4] |
| Astrometry | |
| Proper motion (μ) | RA: 12.654 ± 0.4618[1] mas/yr Dec.: 5.989 ± 0.835[1] mas/yr |
| Parallax (π) | 3.2972 ± 0.1456 mas[5] |
| Distance | 990 ± 40 ly (300 ± 10 pc) |
| Absolute magnitude (MV) | −4.7[6] |
| Details | |
| Mass | 10.1±0.1[7] M☉ |
| Radius | 172.7+7.5 −8.3[8] R☉ |
| Luminosity | 10,024±1,052[8] L☉ |
| Surface gravity (log g) | 0.75[9] cgs |
| Temperature | 4,393±58[8] K |
| Metallicity [Fe/H] | +0.04[8] dex |
| Rotational velocity (v sin i) | 10.64[10] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Zeta Cephei (ζ Cep, ζ Cephei) is a star in the constellation of Cepheus. Zeta Cephei marks the left shoulder of Cepheus, the King of Ethiopia. It is one of the fundamental stars of the MK spectral sequence, defined as type K1.5 Ib.
Characteristics[edit]
Zeta Cephei has a spectral classification of K1.5Ib,[3], indicating that it is a lower luminosity red supergiant star. It is about 173 times larger than the Sun and has a surface temperature of 4,393 K.[8] The luminosity of Zeta Cephei is approximately 10,000 times that of the Sun.[8] At a distance of about 840 light-years,[11] Zeta Cephei has an apparent magnitude (m) of 3.4 and an absolute magnitude (M) of -4.7. The star has a metallicity approximately 1.6 times that of the Sun; i.e., it contains 1.6 times as much heavy-element material as the Sun.
Supernova progenitor[edit]
Zeta Cephei has been listed as a likely pre-supernova candidate by a 2022 study. Having a mass of 10.1 M☉, it might end its life in a core-collapse supernova. It could also provide observable pre-supernova neutrino signals, just hours before the core collapses.[7]
Possible companion star[edit]
Hekker et al. (2008) have detected a periodicity of 533 days, hinting at the possible presence of an as yet unseen companion.[12] It is listed as a possible eclipsing binary with a very small amplitude.[4]
References[edit]
- ^ a b c d 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.
- ^ a b Levesque, Emily M.; Massey, Philip; Olsen, K. A. G.; Plez, Bertrand; Josselin, Eric; Maeder, Andre; Meynet, Georges (2005). "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought". The Astrophysical Journal. 628 (2): 973–985. arXiv:astro-ph/0504337. Bibcode:2005ApJ...628..973L. doi:10.1086/430901. S2CID 15109583.
- ^ a b Morgan, W. W.; Keenan, P. C. (1973). "Spectral Classification". Annual Review of Astronomy and Astrophysics. 11: 29–50. Bibcode:1973ARA&A..11...29M. doi:10.1146/annurev.aa.11.090173.000333.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: 02025. Bibcode:2009yCat....102025S.
- ^ 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.
- ^ Luck, R. E. (1982). "The chemical composition of late-type supergiants. IV - Homogeneous abundances and galactic metallicity trends". Astrophysical Journal. 256: 177. Bibcode:1982ApJ...256..177L. doi:10.1086/159895.
- ^ a b Machado, L. N.; Abe, K.; Hayato, Y.; Hiraide, K.; Ieki, K.; Ikeda, M.; Kameda, J.; Kanemura, Y.; Kaneshima, R.; Kashiwagi, Y.; Kataoka, Y.; Miki, S.; Mine, S.; Miura, M.; Moriyama, S. (2022-08-12). "Pre-supernova Alert System for Super-Kamiokande". The Astrophysical Journal. 935 (1): 40. doi:10.3847/1538-4357/ac7f9c. ISSN 0004-637X.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ a b c d e f Baines, Ellyn K.; Armstrong, J. Thomas; Clark III, James H.; Gorney, Jim; Hutter, Donald J.; Jorgensen, Anders M.; Kyte, Casey; Mozurkewich, David; Nisley, Ishara; Sanborn, Jason; Schmitt, Henrique R.; van Belle, Gerard T. (2021-11-01). "Angular Diameters and Fundamental Parameters of Forty-Four Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 162 (5): 198. arXiv:2211.09030. Bibcode:2021AJ....162..198B. doi:10.3847/1538-3881/ac2431. ISSN 0004-6256.
- ^ Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M
- ^ Hekker, S.; Meléndez, J. (2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics. 475 (3): 1003. arXiv:0709.1145. Bibcode:2007A&A...475.1003H. doi:10.1051/0004-6361:20078233. S2CID 10436552.
- ^ van Leeuwen, F. (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.Vizier catalog entry
- ^ Hekker; et al. (2008). "Precise radial velocities of giant stars. IV. A correlation between surface gravity and radial velocity variation and a statistical investigation of companion properties". Astronomy and Astrophysics. 480 (1): 215–222. arXiv:0801.0741. Bibcode:2008A&A...480..215H. doi:10.1051/0004-6361:20078321. S2CID 33442610.
