57 Geminorum (57 Gem) is a yellow giant star in the constellation Gemini, with an apparent magnitude of 5.0. At a distance of about 179 light years, it has a luminosity about 29 times the Sun's. With an age of about 1.2 billion years, it has evolved away from the main sequence and expanded to seven times the width of the Sun.
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Gemini |
| Right ascension | 07h 23m 28.511s[1] |
| Declination | +25° 03′ 01.91″[1] |
| Apparent magnitude (V) | 5.018[2] |
| Characteristics | |
| Spectral type | G8III[3] |
| U−B color index | +1.778[2] |
| B−V color index | +0.174[2] |
| Astrometry | |
| Radial velocity (Rv) | 5.43±0.13[1] km/s |
| Proper motion (μ) | RA: −66.676[1] mas/yr Dec.: −29.082[1] mas/yr |
| Parallax (π) | 18.1774 ± 0.1459 mas[1] |
| Distance | 179 ± 1 ly (55.0 ± 0.4 pc) |
| Absolute magnitude (MV) | 1.66[4] |
| Details | |
| Mass | 2.2[5] M☉ |
| Radius | 7.1[1] R☉ |
| Luminosity | 29[1] L☉ |
| Surface gravity (log g) | 2.84[4] cgs |
| Temperature | 4,902[4] K |
| Metallicity [Fe/H] | 0.21[4] dex |
| Rotational velocity (v sin i) | 1.3[6] km/s |
| Age | 1.2[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
57 Geminorum is the star's Flamsteed designation. It also has the rarely-used Bayer designation A Geminorum.
The radial velocity of 57 Geminorum has been closely examined for indications that it may have orbiting exoplanets, but it shows a particularly stable radial velocity.[8][9]
References
edit- ^ 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 Paunzen, E. (2022). "Catalogue of stars measured in the Geneva seven-colour photometric system". Astronomy and Astrophysics. 661: A89. arXiv:2111.04810. Bibcode:2022A&A...661A..89P. doi:10.1051/0004-6361/202142355. S2CID 244728366.
- ^ Harlan, E. A. (September 1969). "Mk classifications for F and G-type stars". Astronomical Journal. 74: 916. Bibcode:1969AJ.....74..916H. doi:10.1086/110881.
- ^ a b c d Schiavon, Ricardo P. (July 2007). "Population Synthesis in the Blue. IV. Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations". The Astrophysical Journal Supplement Series. 171 (1): 146–205. arXiv:astro-ph/0611464. Bibcode:2007ApJS..171..146S. doi:10.1086/511753. S2CID 13946698.
- ^ Queiroz, A. B. A.; Anders, F.; Chiappini, C.; Khalatyan, A.; Santiago, B. X.; Steinmetz, M.; Valentini, M.; Miglio, A.; Bossini, D.; Barbuy, B.; Minchev, I.; Minniti, D.; García Hernández, D. A.; Schultheis, M.; Beaton, R. L.; Beers, T. C.; Bizyaev, D.; Brownstein, J. R.; Cunha, K.; Fernández-Trincado, J. G.; Frinchaboy, P. M.; Lane, R. R.; Majewski, S. R.; Nataf, D.; Nitschelm, C.; Pan, K.; Roman-Lopes, A.; Sobeck, J. S.; Stringfellow, G.; Zamora, O. (2020). "From the bulge to the outer disc: StarHorse stellar parameters, distances, and extinctions for stars in APOGEE DR16 and other spectroscopic surveys". Astronomy and Astrophysics. 638: A76. arXiv:1912.09778. Bibcode:2020A&A...638A..76Q. doi:10.1051/0004-6361/201937364. S2CID 209439697.
- ^ Glebocki, R.; Gnacinski, P. (2005). "VizieR Online Data Catalog: Catalog of Stellar Rotational Velocities (Glebocki+ 2005)". VizieR On-line Data Catalog: III/244. Originally Published in: 2005csss...13..571G; 2005yCat.3244....0G. 3244. Bibcode:2005yCat.3244....0G.
- ^ Takeda, Yoichi; et al. (August 2008). "Stellar parameters and elemental abundances of late-G giants". Publications of the Astronomical Society of Japan. 60 (4): 781–802. arXiv:0805.2434. Bibcode:2008PASJ...60..781T. doi:10.1093/pasj/60.4.781.
- ^ Sato; et al. (2005). "Radial-Velocity Variability of G-Type Giants: First Three Years of the Okayama Planet Search Program". Publications of the Astronomical Society of Japan. 57 (1): 97–107. Bibcode:2005PASJ...57...97S. doi:10.1093/pasj/57.1.97.
- ^ Isaacson, Howard; et al. (2010). "Chromospheric Activity and Jitter Measurements for 2630 Stars on the California Planet Search". The Astrophysical Journal. 725 (1): 875–885. arXiv:1009.2301. Bibcode:2010ApJ...725..875I. doi:10.1088/0004-637X/725/1/875. S2CID 118577960.