Pi Andromedae
| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 36m 52.84926s[1] |
| Declination | +33° 43′ 09.6384″[1] |
| Apparent magnitude (V) | 4.36[2] (4.9/5.3)[3] |
| Characteristics | |
| Spectral type | B5 V[4] (B5 V + B5 V[3]) |
| U−B color index | –0.55[2] |
| B−V color index | –0.16[2] |
| Astrometry | |
| Radial velocity (Rv) | +8.7[5] km/s |
| Proper motion (μ) | RA: +14.75[1] mas/yr Dec.: –3.51[1] mas/yr |
| Parallax (π) | 5.45 ± 0.31[1] mas |
| Distance | 600 ± 30 ly (180 ± 10 pc) |
| Details | |
| Surface gravity (log g) | 4.10[4] cgs |
| Temperature | 15,276[4] K |
| Metallicity [Fe/H] | –0.20[4] dex |
| Rotational velocity (v sin i) | 25[6] km/s |
| Other designations | |
Pi Andromedae (Pi And, π Andromedae, π And) is the Bayer designation for a binary star[3] system in the northern constellation of Andromeda. With an apparent visual magnitude of 4.4,[2] it is visible to the naked eye. It is located approximately 600 light-years (180 parsecs) from Earth.
The pair is classified as a blue-white B-type main sequence dwarf with an apparent magnitude of +4.34. It is a spectroscopic binary with an orbital period of 143.6 days and an eccentricity of 0.56. There is a magnitude 8.6 companion 35.9 arcseconds away.[3] At 55 arcseconds separation is an 11th magnitude companion.
Naming
In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism consisting of π Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, ν Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, π Andromedae itself is known as 奎宿六 (Kuí Sù liù, English: the Sixth Star of Legs.)[7]
References
- 1 2 3 4 5 van Leeuwen, F. (November 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. - 1 2 3 4 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
- 1 2 3 4 Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.
- 1 2 3 4 Cenarro, A. J.; et al. (January 2007), "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters", Monthly Notices of the Royal Astronomical Society, 374 (2): 664–690, arXiv:astro-ph/0611618, Bibcode:2007MNRAS.374..664C, doi:10.1111/j.1365-2966.2006.11196.x.
- ↑ Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
- ↑ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日