Lambda Piscium

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

Location of λ Piscium(circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension 23h 42m 02.8062s
Declination +1° 46′ 48.147″
Apparent magnitude (V) 4.49
Spectral type A7V[2]
U−B color index +0.07
B−V color index +0.21
Radial velocity (Rv) +12.4 km/s
Proper motion (μ) RA: -129.55 mas/yr
Dec.: -154.87 mas/yr
Parallax (π) 32.38 ± 0.84 mas
Distance 101 ± 3 ly
(30.9 ± 0.8 pc)
Mass 1.806[2] M
Radius 2.0403±0.0451[2] R
Luminosity 13.3897±0.1692[2] L
Temperature 7734±80[2] K
Age 900[2] Myr
Other designations
λ Piscium, λ Psc, Lambda Psc, 18 Piscium, BD+00°5037, FK5 1620, GC 32917, HD 222603, HIP 116928, HR 8984, PPM 174348, SAO 128336.
Database references

Lambda Piscium (Lambda Psc, λ Piscium, λ Psc) is a star approximately 101 light years away from Earth in the constellation Pisces. It is a bluish-white star of A7V spectral classification, meaning it has a surface temperature of 7,500 to 11,000 kelvins. It is much brighter and hotter in surface temperature than the Sun, yet is approximately the same size.[3] Lambda Piscium forms the southeast corner of the "Circlet" in Pisces.[4]


In Chinese, 雲雨 (Yún Yǔ), meaning Cloud and Rain, refers to an asterism consisting of λ Piscium, κ Piscium, 12 Piscium and 21 Piscium. Consequently, λ Piscium itself is known as 雲雨四 (Yún Yǔ sì, English: the Fourth Star of Cloud and Rain.)[5]


  1. ^ "Simbad Query Result". Simbad. Retrieved September 30, 2007. 
  2. ^ a b c d e f Boyajian, Tabetha S.; et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal, 771 (1): 31, arXiv:1306.2974Freely accessible, Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40, 40.  See Table 3.
  3. ^ "Hipparcos Star Catalog Entry". Retrieved September 30, 2007. 
  4. ^ " - Meteor Watch, September 1-7, 2000". Retrieved September 30, 2007. 
  5. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 8 日