Kappa Piscium

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Kappa Piscium[1]
Diagram showing star positions and boundaries of the Pisces constellation and its surroundings
Cercle rouge 100%.svg

Location of κ Piscium(circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension 23h 26m 55.9553s
Declination +1° 15' 20.189"
Apparent magnitude (V) 4.927
Spectral type A0pCrSrSi
U−B color index -0.03
B−V color index +0.04
Variable type alpha2-CVn
Radial velocity (Rv) -3.2 km/s
Proper motion (μ) RA: 85.60 mas/yr
Dec.: -94.43 mas/yr
Parallax (π) 20.12 ± 0.79 mas
Distance 162 ± 6 ly
(50 ± 2 pc)
Other designations
κ Piscium, 8 Piscium, BD+00 4998, CCDM J23269+0116A, FK5 884, GC 32620, HD 220825, HIP 115738, HR 8911, IDS 23218+0042 A, PPM 174092, SAO 128186, WDS J23269+0115A
Database references

Kappa Piscium (Kappa Psc, κ Piscium, κ Psc) is a multiple star approximately 162 light years away from Earth, in the constellation Pisces. Appearing as a single point in the sky, it is easily split when viewed with a pair of binoculars, and consists of three components. One star has an apparent magnitude of 4.87 at maximum brightness and 4.95 at minimum brightness, while the other has an apparent magnitude of 11.9.[2][3]

The brighter component is a variable star, meaning its brightness fluctuates by a magnitude of 0.01 to 0.1. Specifically, it is an Alpha² Canum Venaticorum variable, a star with strong magnetic fields and strong silicon, strontium, and chromium spectral lines. It also shows many lines of uranium, and possibly the rare element holmium. Its uranium and osmium content could have been caused by a nearby supernova. It is deficient in oxygen relative to magnesium.[2][3]

The star rotates approximately once every 48 hours at a velocity of about 41 km/s. As it is a class A star, it possesses a surface temperature between 7,500 and 11,000 kelvins.[2]


In Chinese, 雲雨 (Yún Yǔ), meaning Cloud and Rain, refers to an asterism consisting of refers to an asterism consisting of κ Piscium, 12 Piscium, 21 Piscium and λ Piscium. Consequently, κ Piscium itself is known as 雲雨一 (Yún Yǔ yī, English: the First Star of Cloud and Rain.)[4]


  1. ^ "Simbad Query Result". Simbad. Retrieved September 30, 2007. 
  2. ^ a b c "kappa Piscium". Retrieved September 30, 2007. 
  3. ^ a b "Whats_Up_November.pdf" (PDF). Retrieved September 30, 2007. [dead link]
  4. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 8 日