Epsilon Piscium
Star in the constellation Pisces
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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. This is a giant star, slightly cooler in surface temperature, yet brighter and larger than the Sun.[5] It is a suspected occultation double, with both stars having the same magnitude, separated by 0.25 arcsecond.[8]
 | |
| 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 mas[2] |
| Distance | 182 ± 2 ly (55.7 ± 0.7 pc) |
| Absolute magnitude (MV) | 0.44[4] |
| Details | |
| Mass | 2.27[4] M☉ |
| Radius | 11.41±0.14[5] R☉ |
| Luminosity | 62.2±0.1[5] L☉ |
| Surface gravity (log g) | 2.99[6] cgs |
| Temperature | 4,797±22[5] K |
| Metallicity [Fe/H] | −0.39[6] dex |
| Age | 2.56[7] Gyr |
| Other designations | |
| ε Piscium, ε Psc, Epsilon Psc, 71 Piscium, BD+07 153, FK5 36, GC 1258, HD 6186, HIP 4906, HR 294, PPM 144204, SAO 109627. | |
| 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.)[9] In Japanese, 悠翔星 (Haruto-boshi), meaning "Soaring Forever Star," refers to the Japanese description of ε Piscium.
Planetary system
In 2021, a gas giant planetary candidate was detected by radial velocity method.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | >0.77+0.16 −0.10 MJ |
0.88+0.11 −0.10 |
255.3+2.1 −1.4 |
0.278+0.122 −0.186 |
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