Gamma Piscium

Gamma Piscium (Gamma Psc, γ Piscium, γ Psc) is a star approximately 138 light years away from Earth,[1] 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.

γ Piscium
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 mas[1]
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, 2MASS J23170996+0316563[6]
Database references
SIMBADdata

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 is part of the asterism known as the "circlet of Pisces."[7]

Naming

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, the Chinese name for γ Piscium itself is 霹靂二 (Pī Lì èr, English: the Second Star of Thunderbolt.)[8]

Planetary system

In 2021, a gas giant planet was detected by the radial velocity method.[9]

The Gamma Piscium planetary system[9]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b >1.34+0.02
−0.31 MJ		 1.32+0.05
−0.08		 555.1+6.0
−2.5		 0.204+0.114
−0.141		 — —

In fiction

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

References
  1. van Leeuwen, Floor (13 August 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. eISSN 1432-0746. ISSN 0004-6361. Vizier catalog entry
  2. Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C
  3. Baines, Ellyn K.; et al. (2018). "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 155 (1). 30. arXiv:1712.08109. Bibcode:2018AJ....155...30B. doi:10.3847/1538-3881/aa9d8b. S2CID 119427037.
  4. Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg, Astronomisches Rechen-Institut Heidelberg, 35 (35): 1, Bibcode:1999VeARI..35....1W
  5. 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, S2CID 9341088
  6. "* gam Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 30, 2007.
  7. "SPACE.com -- SpaceWatch -- Pisces Rising". Space.com. Archived from the original on July 13, 2010. Retrieved September 30, 2007.
  8. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 8 日
  9. Teng, Huan-Yu; Sato, Bun'ei; Takarada, Takuya; Omiya, Masashi; Harakawa, Hiroki; Izumiura, Hideyuki; Kambe, Eiji; Takeda, Yoichi; Yoshida, Michitoshi; Itoh, Yoichi; Ando, Hiroyasu; Kokubo, Eiichiro (2022), "Regular radial velocity variations in nine G- and K-type giant stars: Eight planets and one planet candidate", Publications of the Astronomical Society of Japan, 74: 92–127, arXiv:2112.07169, doi:10.1093/pasj/psab112
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.