Gamma Piscium

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γ Piscium
Pisces constellation map.svg
Red circle.svg
Location of γ Piscium (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension  23h 17m 09.93749s[1]
Declination +03° 16′ 56.2380″[1]
Apparent magnitude (V) 3.699[2]
Characteristics
Spectral type G8 III[3]
U−B color index +0.572 [2]
B−V color index +0.924[2]
Astrometry
Radial velocity (Rv)-13.6[4] km/s
Proper motion (μ) RA: 759.82[1] mas/yr
Dec.: 17.77[1] mas/yr
Parallax (π)23.64 ± 0.18[1] mas
Distance138 ± 1 ly
(42.3 ± 0.3 pc)
Absolute magnitude (MV)0.68 ± 0.08[5]
Details
Mass1.11±0.29[3] M
Radius11.28±0.10[3] R
Luminosity62.7±3.3[3] L
Surface gravity (log g)2.43 ± 0.06[5] cgs
Temperature4833±62[3] K
Metallicity [Fe/H]−0.51[5] dex
Age4.58±3.10[3] Gyr
Other designations
γ Piscium, 6 Piscium, BD+02°4648, FK5 878, GC 32415, HD 219615, HIP 114971, HR 8852, PPM 173938, SAO 128085, GC 32415.[6]
Database references
SIMBADdata

Gamma Piscium (Gamma Psc, γ Piscium, γ Psc) is a star approximately 138 light years away from Earth,[7] in the zodiac constellation of Pisces. It is a yellow star with a spectral type of G8 III, meaning it has a surface temperature of 4,833 K and is a giant star. It is slightly cooler than the Sun, yet it is 11[3] solar radii in size and shines with the light of 63 Suns.[3] At an apparent magnitude of 3.7,[2] it is the second brightest star in the constellation Pisces, between Eta and Alpha. Once a white A2 star, it is 5.5 billion years old.

Gamma Piscium moves across the sky at three-quarters of an arcsecond per year, which at 138 light years corresponds to 153 kilometers per second. This suggests it is a visitor from another part of the Milky Way Galaxy; in astronomical terms, it will quickly leave the vicinity of the Sun. Its metallicity is only one-fourth that of the Sun, and visitors from outside the thin disk that composes the Milky Way tend to be metal-poor. Gamma Piscium lies inside an asterism known as the "circlet of Pisces."[8]

Naming[edit]

In Chinese, 霹靂 (Pī Lì), meaning Thunderbolt, refers to an asterism consisting of γ Piscium, β Piscium, θ Piscium, ι Piscium and ω Piscium. Consequently, γ Piscium itself is known as 霹靂二 (Pī Lì èr, English: the Second Star of Thunderbolt.)[9]

In fiction[edit]

In Frank Herbert's Dune series, Gamma Waiping (The Chinese name for Pisces) is the home system of Imperial House Corrino.[citation needed]

References[edit]

  1. ^ a b c d e 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
  2. ^ a b c d Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C
  3. ^ a b c d e f g h Baines, Ellyn K.; et al. (2018). "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 155. 30. arXiv:1712.08109. Bibcode:2018AJ....155...30B. doi:10.3847/1538-3881/aa9d8b.
  4. ^ Wielen, R.; et al. (1999), Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions (35), Astronomisches Rechen-Institut Heidelberg, Bibcode:1999VeARI..35....1W
  5. ^ a b c da Silva, L.; et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics, 458 (2): 609–623, arXiv:astro-ph/0608160, Bibcode:2006A&A...458..609D, doi:10.1051/0004-6361:20065105
  6. ^ "* gam Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 30, 2007.
  7. ^ van Leeuwen, F. (2007), "HIP 114971", Hipparcos, the New Reduction, retrieved 2010-08-30
  8. ^ "SPACE.com -- SpaceWatch -- Pisces Rising". Retrieved September 30, 2007.
  9. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 8 日