Omicron Piscium

From Wikipedia, the free encyclopedia
  (Redirected from 110 Piscium)
Jump to: navigation, search
Omicron Piscium
Pisces IAU.svg
Red circle.svg

Location of ο Piscium (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Pisces
Right ascension 01h 45m 23.63185s[1]
Declination +09° 09′ 27.8530″[1]
Apparent magnitude (V) 4.27[2]
Spectral type K0 III[2]
U−B color index +0.736[3]
B−V color index +0.959[3]
Proper motion (μ) RA: +72.98[1] mas/yr
Dec.: +39.30[1] mas/yr
Parallax (π) 11.67 ± 0.67[1] mas
Distance 280 ± 20 ly
(86 ± 5 pc)
Absolute magnitude (MV) −0.22[2]
Mass 3.03 M
Radius 14.57 R
Luminosity 132 L
Surface gravity (log g) 2.57 cgs
Temperature 5,004 K
Metallicity [Fe/H] 0.10 dex
Rotational velocity (v sin i) 2.88 km/s
Age 390 Myr
Other designations
Torcularis Septentrionalis, ο Psc, 110 Piscium, BD+08° 273, FK5 60, GC 2139, HD 10761, HIP 8198, HR 510, SAO 110110, PPM 144950[5]
Database references

Omicron Piscium (ο Piscium) is a star in the constellation Pisces. It can be viewed with the naked eye, having an apparent visual magnitude of 4.27.[2] Based upon an annual parallax shift of 11.67 mas as seen from the Earth,[1] the star is located roughly 280 light years from the Sun. The star is positioned near the ecliptic, so it is subject to occultation by the Moon,[6] it is a member of the thin disk population of the Milky Way.[4]

This is a probable astrometric binary system,[7] the visible component is an evolved K-type giant star with a stellar classification of K0 III.[2] At the estimated age of 390 million years,[4] it is most likely (76% chance) on the horizontal branch, rather than the red giant branch,[8] as such, it is a red clump star that is generating energy through helium fusion at its core.[9] The star has three times the mass of the Sun and has expanded to over 14 times the Sun's radius, it is radiating 132 times the Sun's luminosity from its photosphere at an effective temperature of 5,004 K.[4]

Name and etymology[edit]

The star has the traditional name Torcularis septentrionalis, taken from the 1515 Almagest. According to Allen (1899), the name is translated from the Greek ληνός, which was "erroneously written for λίνος".[10]

In Chinese, 右更 (Yòu Gèng), meaning Official in Charge of the Pasturing, refers to an asterism consisting of ο Piscium, η Piscium, ρ Piscium, π Piscium and 104 Piscium. Consequently, ο Piscium itself is known as 右更四 (Yòu Gèng sì, English: the Fourth Star of Official in Charge of the Pasturing.)[11]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d e Setiawan, J.; et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, 421: 241−254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1. 
  3. ^ a b 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: 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667. 
  4. ^ a b c d Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422Freely accessible, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474. 
  5. ^ "omi Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-25. 
  6. ^ Richichi, A.; et al. (January 2016), "Lunar Occultations of 18 Stellar Sources from the 2.4 m Thai National Telescope", The Astronomical Journal, 151 (1): 5, Bibcode:2016AJ....151...10R, doi:10.3847/0004-6256/151/1/10, 10. 
  7. ^ 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:0806.2878Freely accessible, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x. 
  8. ^ Reffert, Sabine; et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy and Astrophysics, 574A (2): 116–129, arXiv:1412.4634Freely accessible, Bibcode:2015A&A...574A.116R, doi:10.1051/0004-6361/201322360. 
  9. ^ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329Freely accessible, Bibcode:2000ApJ...539..732A, doi:10.1086/309278. 
  10. ^ Allen, Richard Hinckley (1963), "Pisces, the Fishes", Star Names — Their Lore and Meaning, Dover 
  11. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日