Alpha Piscium
 Location of α Piscium(circled) |
|
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Pisces |
| Right ascension | 02h 02m 02.81972s[1] |
| Declination | +02° 45′ 49.5410″[1] |
| Apparent magnitude (V) | 3.82[2] (+4.33 + 5.23)[3] |
| Distance | 139 ± 1.6 ly (46.2 ± 0.5[1] pc) |
| Spectral type | A0pSiSr + A3m[3] |
| Other designations | |
Alpha Piscium (Alpha Psc, α Piscium, α Psc) is the Bayer designation for a star in the equatorial constellation of Pisces. It has the traditional name Alrescha (Al Rescha, Alrischa, Alrisha).
The distance to α Psc is about 139 light years. The system comprises a close double star with angular separation of presently 1.8" between the components. The main star is of magnitude +4.33 and spectral type A0p, while the companion is magnitude 5.23 and belongs to spectral class A3m. The two stars take more than 700 years to orbit one another and they will make their closest approach to each other around 2060. One or both of the stars may be a spectroscopic binary as well. The stars have masses of 2.3 and 1.8 solar masses respectively and shine with a total luminosity of 31 and 12 times that of the Sun.[4]
Name and etymology
- The name Alrescha is from the Arabic الرشآء al-rišā’ "the well rope". Less common names are Kaitain and Okda, the latter from the Arabic عقدة ‘uqdah "knot".[5]
- In Chinese, 外屏 (Wài Píng), meaning Outer Fence, refers to an asterism consisting of α Piscium, δ Piscium, ε Piscium, ζ Piscium, μ Piscium, ν Piscium and ξ Piscium. Consequently, α Piscium itself is known as 外屏七 (Wài Píng qī, English: the Seventh Star of Outer Fence.)[6]
References
- ↑ 1.0 1.1 1.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日
