Epsilon Piscium

Epsilon Piscium (Epsilon Psc, ε Piscium, ε Psc) is the Bayer designation for a star approximately 182 light-years (56 parsecs) away from the Earth,[2] in the constellation Pisces. It is a yellow-orange star of the G9 III or K0 III spectral type, meaning it has a surface temperature around 5,000 kelvins. This is a normal giant star, slightly cooler in surface temperature, yet brighter and larger than the Sun.[8] It is a suspected occultation double, with both stars having the same magnitude, separated by 0.25 arcsecond.[9]

Epsilon Piscium[1]
Location of ε Piscium (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension 01h 02m 56.60862s[2]
Declination +07° 53′ 24.4855″[2]
Apparent magnitude (V) 4.27[3]
Characteristics
Spectral type K0 III[4]
U−B color index +0.691[3]
B−V color index +0.952[4]
Astrometry
Radial velocity (Rv)+7.47±0.20[4] km/s
Proper motion (μ) RA: −80.17±0.19[2] mas/yr
Dec.: +25.59±0.14[2] mas/yr
Parallax (π)17.94 ± 0.21 mas[2]
Distance182 ± 2 ly
(55.7 ± 0.7 pc)
Absolute magnitude (MV)0.44[4]
Details
Mass2.27[4] M☉
Radius10.9±0.8[5] R☉
Luminosity67.6[6] L☉
Surface gravity (log g)2.99[7] cgs
Temperature4,814±40[6] K
Metallicity [Fe/H]−0.39[7] dex
Age2.56[6] Gyr
Other designations
ε Piscium, ε Psc, Epsilon Psc, 71 Piscium, BD+07 153, FK5 36, GC 1258, HD 6186, HIP 4906, HR 294, PPM 144204, SAO 109627.
Database references
SIMBADdata

Naming

In Chinese, 外屏 (Wài Píng), meaning Outer Fence, refers to an asterism consisting of ε Piscium, δ Piscium, ζ Piscium, μ Piscium, ν Piscium, ξ Piscium and α Piscium. Consequently, the Chinese name for ε Piscium itself is 外屏二 (Wài Píng èr, English: the Second Star of Outer Fence.)[10] In Japanese, 悠翔星 (Haruto-boshi), meaning "Soaring Forever Star," refers to the Japanese description of ε Piscium.

Planetary system

In 2021, a gas giant planetary candidate was detected by radial velocity method.[11]

The planetary system[11]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
Espsilon Piscium b (unconfirmed) >0.77+0.16
−0.10 MJ		 0.88+0.11
−0.10		 255.3+2.1
−1.4		 0.278+0.122
−0.186		 — —

References
  1. "* eps Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 1, 2007.
  2. van Leeuwen, F. (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, S2CID 18759600.
  3. Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society, 172 (3): 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
  4. Hekker, S.; et al. (August 2006), "Precise radial velocities of giant stars. I. Stable stars", Astronomy and Astrophysics, 454 (3): 943–949, arXiv:astro-ph/0604502, Bibcode:2006A&A...454..943H, doi:10.1051/0004-6361:20064946, S2CID 119529768
  5. Nordgren, Tyler E.; et al. (December 1999), "Stellar Angular Diameters of Late-Type Giants and Supergiants Measured with the Navy Prototype Optical Interferometer", The Astronomical Journal, 118 (6): 3032–3038, Bibcode:1999AJ....118.3032N, doi:10.1086/301114{{citation}}: CS1 maint: multiple names: authors list (link)
  6. Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
  7. Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
  8. "Hipparcos Star Catalog Entry". Archived from the original on August 7, 2007. Retrieved October 1, 2007.
  9. "VizieR Detailed Page". Retrieved October 1, 2007.
  10. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日
  11. 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.