32 Eridani
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 03h 54m 17.50181s |
| Declination | −02° 57′ 17.0397″ |
| Apparent magnitude (V) | 4.45[1] |
| Observation data Epoch J2000 Equinox J2000 | |
| Constellation | Eridanus |
| 32 Eridani A | |
| Right ascension | 03h 54m 17.50s[2] |
| Declination | −02° 57′ 17.0″[2] |
| Apparent magnitude (V) | 4.79[3] |
| 32 Eridani B | |
| Right ascension | 03h 54m 17.41s[4] |
| Declination | −02° 57′ 10.3″[4] |
| Apparent magnitude (V) | 6.14[3] |
| Characteristics | |
| 32 Eridani A | |
| Evolutionary stage | giant star |
| Spectral type | G8III[5] |
| 32 Eridani B | |
| Evolutionary stage | main sequence[4] |
| Spectral type | A1V[5] |
| Astrometry | |
| A | |
| Proper motion (μ) | RA: +26.330[2] mas/yr Dec.: +0.079[2] mas/yr |
| Parallax (π) | 9.4562±0.1108 mas[2] |
| Distance | 345 ± 4 ly (106 ± 1 pc) |
| B | |
| Proper motion (μ) | RA: +26.878[4] mas/yr Dec.: +1.007[4] mas/yr |
| Parallax (π) | 9.6777±0.0623 mas[4] |
| Distance | 337 ± 2 ly (103.3 ± 0.7 pc) |
| Position (relative to 32 Eridani A) | |
| Component | 32 Eridani B |
| Epoch of observation | 2021 |
| Angular distance | 6.90[6]″ |
| Position angle | 349° |
| Details | |
| 32 Eridani A | |
| Mass | 1.29[7] M☉ |
| Radius | 14.6[8] R☉ |
| Luminosity | 138[9] L☉ |
| Surface gravity (log g) | 2.63[9] cgs |
| Temperature | 4,970[9] K |
| Metallicity [Fe/H] | −0.16[9] dex |
| Rotational velocity (v sin i) | 2.7[10] km/s |
| Age | 706[11] Myr |
| 32 Eridani B | |
| Mass | 2.36[8] M☉ |
| Radius | 2.32[8] R☉ |
| Luminosity | 36[8] L☉ |
| Temperature | 9,294[8] K |
| Rotational velocity (v sin i) | 180[12] km/s |
| Age | 461[4] Myr |
| Other designations | |
| 32 Eri, HIP 18255 | |
| 32 Eridani A: HD 24555, HR 1212 | |
| 32 Eridani B: HD 24554, HR 1211 | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
32 Eridani (abbreviated 32 Eri) is a binary star[13] in the constellation of Eridanus. The two stars are designated HD 24555 (32 Eridani A) and HD 24554 (32 Eridani B). They share a single entry in the Hipparcos catalogue, HIP 18255, but have separate entries in the Bright Star Catalogue, HR 1212 and HR 1211.
32 Eridani is visible to the naked eye as a single star with an apparent magnitude of 4.45.[1] Individually, 32 Eridani A shines at magnitude 4.79 while 32 Eridani B has a magnitude of 6.14.[3] As of 2021, the pair had an angular separation of about 6.90 arcseconds with a position angle of 349°.[6]
Based on measurements of parallax by the Gaia mission, the system lies at a distance of about 340 light-years (22,000,000 AU) from Earth.[2][4]
The primary component, 32 Eridani A, is an evolved yellow giant star of spectral type G8III.[5] It has a radius about 15 times that of the Sun[8] and a luminosity around 138 times solar, with an effective temperature of about 4,970 K.[9]
The secondary component, 32 Eridani B, is a main-sequence star of spectral type A1V.[5] It has a surface temperature of roughly 9,294 K[8] and rotates rapidly with a projected rotational velocity of about 180 km/s, giving the star a noticeably flattened shape due to its rotation.[12]
References
- ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.
- ^ a b c d e f 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.
- ^ a b c Hoffleit, D.; Warren, W. H. (1995). "Bright Star Catalogue, 5th ed". VizieR Online Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
- ^ a b c d e f g h 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.
- ^ a b c d Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series. 176 (1): 216–217. Bibcode:2008ApJS..176..216A. doi:10.1086/525529.
- ^ a b Mason, Brian D.; et al. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Retrieved 2024-01-11.
- ^ Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevič, G.; Monari, G.; Cantat-Gaudin, T.; Weiler, M.; Khan, S.; Miglio, A.; Carrillo, I.; Romero-Gómez, M.; Minchev, I.; De Jong, R. S.; Antoja, T.; Ramos, P.; Steinmetz, M.; Enke, H. (2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765.
- ^ a b c d e f g Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.
- ^ a b c d e Lehtinen, Jyri J.; Spada, Federico; Käpylä, Maarit J.; Olspert, Nigul; Käpylä, Petri J. (2020). "Common dynamo scaling in slowly rotating young and evolved stars". Nature Astronomy. 4 (7): 658. arXiv:2003.08997. Bibcode:2020NatAs...4..658L. doi:10.1038/s41550-020-1039-x.
- ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars. V. Southern stars". Astronomy and Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762.
- ^ Kordopatis, G.; Schultheis, M.; McMillan, P. J.; Palicio, P. A.; De Laverny, P.; Recio-Blanco, A.; Creevey, O.; Álvarez, M. A.; Andrae, R.; Poggio, E.; Spitoni, E.; Contursi, G.; Zhao, H.; Oreshina-Slezak, I.; Ordenovic, C.; Bijaoui, A. (2023). "Stellar ages, masses, extinctions, and orbital parameters based on spectroscopic parameters of Gaia DR3". Astronomy and Astrophysics. 669: A104. arXiv:2206.07937. Bibcode:2023A&A...669A.104K. doi:10.1051/0004-6361/202244283.
- ^ a b van Belle, Gerard T. (2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20 (1) 51. arXiv:1204.2572. Bibcode:2012A&ARv..20...51V. doi:10.1007/s00159-012-0051-2.
- ^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.