Epsilon Piscium
Epsilon Piscium (Epsilon Psc, ε Piscium, ε Psc) is the Bayer designation for a star approximately 182 light-years (56 parsecs) away from the Earth,[2] in the constellation Pisces. It is a yellow-orange star of the G9 III or K0 III spectral type, meaning it has a surface temperature around 5,000 kelvins. This is a normal giant star, slightly cooler in surface temperature, yet brighter and larger than the Sun.[8] It is a suspected occultation double, with both stars having the same magnitude, separated by 0.25 arcsecond.[9]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Pisces |
Right ascension | 01h 02m 56.60862s[2] |
Declination | +07° 53′ 24.4855″[2] |
Apparent magnitude (V) | 4.27[3] |
Characteristics | |
Spectral type | K0 III[4] |
U−B color index | +0.691[3] |
B−V color index | +0.952[4] |
Astrometry | |
Radial velocity (Rv) | +7.47±0.20[4] km/s |
Proper motion (μ) | RA: −80.17±0.19[2] mas/yr Dec.: +25.59±0.14[2] mas/yr |
Parallax (π) | 17.94 ± 0.21[2] mas |
Distance | 182 ± 2 ly (55.7 ± 0.7 pc) |
Absolute magnitude (MV) | 0.44[4] |
Details | |
Mass | 2.27[4] M☉ |
Radius | 10.9±0.8[5] R☉ |
Luminosity | 67.6[6] L☉ |
Surface gravity (log g) | 2.99[7] cgs |
Temperature | 4,814±40[6] K |
Metallicity [Fe/H] | −0.39[7] dex |
Age | 2.56[6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Naming
In Chinese, 外屏 (Wài Píng), meaning Outer Fence, refers to an asterism consisting of ε Piscium, δ Piscium, ζ Piscium, μ Piscium, ν Piscium, ξ Piscium and α Piscium. Consequently, the Chinese name for ε Piscium itself is 外屏二 (Wài Píng èr, English: the Second Star of Outer Fence.)[10] In Japanese, 悠翔星 (Haruto-boshi), meaning "Soaring Forever Star," refers to the Japanese description of ε Piscium.
References
- "* eps Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 1, 2007.
- 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.
- Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society, 172: 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
- Hekker, S.; et al. (August 2006), "Precise radial velocities of giant stars. I. Stable stars", Astronomy and Astrophysics, 454 (3): 943–949, arXiv:astro-ph/0604502, Bibcode:2006A&A...454..943H, doi:10.1051/0004-6361:20064946
- Nordgren, Tyler E.; et al. (December 1999), "Stellar Angular Diameters of Late-Type Giants and Supergiants Measured with the Navy Prototype Optical Interferometer", The Astronomical Journal, 118 (6): 3032–3038, Bibcode:1999AJ....118.3032N, doi:10.1086/301114
- Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88.
- Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247.
- "Hipparcos Star Catalog Entry". Archived from the original on August 7, 2007. Retrieved October 1, 2007.
- "VizieR Detailed Page". Retrieved October 1, 2007.
- (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日