| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 21h 46m 04.364s[1] |
| Declination | +22° 56′ 55.96″[1] |
| Apparent magnitude (V) | +5.266[2] |
| Characteristics | |
| Evolutionary stage | Supergiant |
| Spectral type | K0IbHdel0.5[3] |
| U−B color index | +1.33[4] |
| B−V color index | +1.41[4] |
| Astrometry | |
| Radial velocity (Rv) | −10.14±0.20[5] km/s |
| Proper motion (μ) | RA: 8.299[1] mas/yr[1] Dec.: −2.478 mas/yr[1] |
| Parallax (π) | 2.3673±0.1279 mas[1] |
| Distance | 1,380 ± 70 ly (420 ± 20 pc) |
| Absolute magnitude (MV) | −4.03[4] |
| Details | |
| Mass | 6.3[6] M☉ |
| Radius | 81[7] R☉ |
| Luminosity | 1,722–1,820[7] L☉ |
| Surface gravity (log g) | 1.11[8] cgs |
| Temperature | 4,185[7] K |
| Metallicity [Fe/H] | +0.03[8] dex |
| Rotational velocity (v sin i) | 19.5[9] km/s |
| Age | 19.8[6] Myr |
| Other designations | |
| 12 Peg, BD+22°4472, FK5 3739, GC 30479, HD 207089, HIP 107472, HR 8321, SAO 89962, PPM 113549[10] | |
| Database references | |
| SIMBAD | data |
12 Pegasi is a K-type supergiant star in the northern constellation of Pegasus. It is faintly visible to the naked eye with an apparent visual magnitude of +5.3.[2] Based on parallax measurements, it is located at a distance of approximately 1,380 light-years (420 pc) from the Earth. The star is drifting closer with a line of sight velocity component of −10.1 km/s.[5]
This evolved star has a spectral type of K0Ib Hdel0.5,[11] which indicates that it is a less luminous K-type supergiant with strong H-δ Balmer lines. It is an estimated 20[6] million years old and is spinning with a projected rotational velocity of 19.5 km/s.[9] With 6.3 times the mass of the Sun,[6] it has expanded to 81 times the radius of the Sun. The star is radiating 1,722–1,820[7] times the luminosity of the Sun from its photosphere at an effective temperature of 4,185 K.[7]
References
[edit]- ^ a b c d e 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.
- ^ a b Høg, E.; et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ 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. ISSN 0067-0049.
- ^ a b c Melnik, A. M.; Dambis, A. K. (2020). "VizieR Online Data Catalog: Kinematic data for high luminosity stars (Melnik+, 2020)". Vizier Online Data Catalog (Other). Bibcode:2020yCatp017036502M.
- ^ a b 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 c d Tetzlaff, N.; et al. (January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
- ^ a b c d e Messineo, M.; Brown, A. G. A. (July 2019). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal. 158 (1): 20. arXiv:1905.03744. Bibcode:2019AJ....158...20M. doi:10.3847/1538-3881/ab1cbd. ISSN 0004-6256. S2CID 148571616.
- ^ a b Wu, Yue; et al. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics. 525: A71. arXiv:1009.1491. Bibcode:2011A&A...525A..71W. doi:10.1051/0004-6361/201015014. S2CID 53480665.
- ^ a b De Medeiros, J. R.; et al. (2002). "A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars" (PDF). Astronomy and Astrophysics. 395: 97–98. Bibcode:2002A&A...395...97D. doi:10.1051/0004-6361:20021214.
- ^ "12 Peg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2026-03-28.
- ^ 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: 245–266. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. ISSN 0067-0049. S2CID 123149047.
