Eta Piscium

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Eta Piscium
Diagram showing star positions and boundaries of the Pisces constellation and its surroundings
Cercle rouge 100%.svg

Location of η Piscium(circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension 01h 31m 29.0s
Declination +15° 20' 45"
Apparent magnitude (V) +3.62
Distance 294 ly
(90 pc)
Spectral type G7IIIa
Other designations
η Piscium, η Psc, Eta Psc, 99 Piscium, BD+14 231, CCDM J01315+1521AB, FK5 50, GC 1839, HD 9270, HIP 7097, HR 437, IDS 01261+1450, PPM 117418, SAO 92484, WDS J01315+1521AB.

Eta Piscium (Eta Psc, η Piscium, η Psc) is the brightest star in the constellation Pisces. Eta Piscium is located at a distance of about 294 light years from Earth, and shines at magnitude +3.62. It is of Spectral type G7 III.

The total luminosity of this star is 316 times that of the Sun, while its surface temperature is 4930 kelvin. The star has a radius of 26 ± 2[1] solar radii, while its mass is 3.5 to 4 solar masses.

Eta Piscium has a faint companion star with a separation of about 1".

Name and etymology[edit]

  • The star had an obscure Babylonian name Kullat Nūnu−the latter being the Babylonian word for fish and the former "Kullat" referring to either a bucket or the cord that ties the fish together.[2]
  • In Chinese, 右更 (Yòu Gèng), meaning Official in Charge of the Pasturing, refers to an asterism consisting of η Piscium, ρ Piscium, π Piscium, ο Piscium and 104 Piscium. Consequently, η Piscium itself is known as 右更二 (Yòu Gèng èr, English: the Second Star of Official in Charge of the Pasturing.)[3]


  1. ^ 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 
  2. ^ Allen, Richard Hinckley, (1963) [1899]. Star Names: Their Lore and Meaning (rep. ed.). New York, NY: Dover Publications Inc. pp. 328–29. ISBN 0-486-21079-0. 
  3. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日

External links[edit]