21 Persei

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21 Persei
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Perseus
Right ascension 02h 57m 17.28220s [1]
Declination +31° 56′ 03.1871″ [1]
Spectral type B9p...

21 Persei is an star in the constellation Perseus. Its apparent magnitude is 5.10. Located around 98.03 parsecs (319.7 ly) distant, it is an hot blue star of spectral type B9.[1] The star is an Alpha2 Canum Venaticorum variable, meaning that the star has a strong magnetic field chromium, silicon, and strontium spectral lines. 21 Persei's period is approximately 2.88 days[2]


  1. ^ a b c "LT Persei". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 28 December 2013. 
  2. ^ Catalano, F. A.; Renson, P.; Leone, F. "Third supplement to the catalogue of observed periods of Ap stars" (PDF). Astronomy and Astrophysics Supplement Series. 98 (2): 269–273. Bibcode:1993A&AS...98..269C.