Upsilon Piscium
A-type main sequence star in the constellation Pisces
From Wikipedia, the free encyclopedia
Upsilon Piscium is a solitary,[10] white-hued star in the zodiac constellation of Pisces. It is faintly visible to the naked eye, having an apparent visual magnitude of +4.75.[2] Based upon an annual parallax shift of 10.59 mas as seen from Earth,[1] it is located about 308 light years from the Sun. The star is drifting further away with a heliocentric radial velocity of +6 km/s.[4]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Pisces |
| Right ascension | 01h 19m 27.99289s[1] |
| Declination | +27° 15′ 50.6155″[1] |
| Apparent magnitude (V) | 4.752[2] |
| Characteristics | |
| Spectral type | A3 V[3] |
| U−B color index | +0.10[2] |
| B−V color index | +0.03[2] |
| Astrometry | |
| Radial velocity (Rv) | +5.8±2.7[4] km/s |
| Proper motion (μ) | RA: +22.98[1] mas/yr Dec.: −11.12[1] mas/yr |
| Parallax (π) | 10.59±0.25 mas[1] |
| Distance | 308 ± 7 ly (94 ± 2 pc) |
| Absolute magnitude (MV) | −0.13[5] |
| Details | |
| Mass | 2.84±0.05[3] M☉ |
| Radius | 2.2[6] R☉ |
| Luminosity | 117[3] L☉ |
| Surface gravity (log g) | 3.59[7] cgs |
| Temperature | 9,183±312[7] K |
| Metallicity [Fe/H] | +0.00±0.05[8] dex |
| Rotational velocity (v sin i) | 91[3] km/s |
| Age | 461[7] Myr |
| Other designations | |
| υ Psc, 90 Piscium, BD+26°220, FK5 45, HD 7964, HIP 6193, HR 383, SAO 74637[9] | |
| Database references | |
| SIMBAD | data |
This is an ordinary A-type main sequence star with a stellar classification of A3 V.[3] It is 461[7] million years old – about 98% of the way through its main sequence lifetime[3] – and is spinning with a projected rotational velocity of 91 km/s.[3] The star has 2.8[3] times the mass of the Sun, about 2.2[6] times the Sun's radius, and is radiating 117[3] times the Sun's luminosity from its photosphere at an effective temperature of 9183 K.[7]
Naming
υ Piscium is the Bayer designation for this star, which is Latinized as Upsilon Piscium. It has the Flamsteed designation 90 Piscium.[9]
In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism composed of υ Piscium, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, π Andromedae, ν Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, the Chinese name for υ Piscium itself is 奎宿十三 (Kuí Sù shí sān, English: the Thirteenth Star of Legs.)[11]