Kappa Cassiopeiae

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Kappa Cassiopeiae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia
Right ascension 00h 32m 59.991s[1]
Declination +62° 55′ 54.42″[1]
Apparent magnitude (V) 4.189
Spectral type B1Iae
Apparent magnitude (U) 3.50
Apparent magnitude (B) 4.276
Apparent magnitude (J) 4.141
Apparent magnitude (H) 4.148
Apparent magnitude (K) 4.013
U−B color index -0.776
B−V color index +0.0869
J−H color index -0.0069
J−K color index +0.128
Variable type α Cyg
Radial velocity (Rv) -2.3 km/s
Proper motion (μ) RA: 3.65 ± 0.17[1] mas/yr
Dec.: –2.07 ± 0.16[1] mas/yr
Parallax (π) 0.73 ± 0.17[1] mas
Distance approx. 4,000 ly
(approx. 1,400 pc)
Absolute magnitude (MV) -6.32
Radius 41.4[2] R
Luminosity 330,000[2] L
Surface gravity (log g) 2.6[2] cgs
Temperature 21,500[2] K
Rotational velocity (v sin i) 91[2] km/s
Other designations
15 Cassiopeiae, HR 130, HD 2905, BD+62°102, FK5 16, HIP 2599, SAO 11256, GC 645
The Bayer-designated stars in Cassiopeia. Kappa Cassiopeiae is circled.

Kappa Cassiopeiae (κ Cas, κ Cassiopeiae) is a star in the constellation Cassiopeia.

κ Cassiopeiae is a blue-white B-type supergiant with a mean apparent magnitude of +4.17. It is approximately 4000 light years from Earth.[1] It is classified as an Alpha Cygni type variable star and its brightness varies from magnitude +4.22 to +4.30.

It is a runaway star, moving at around 2.5 million mph relative to its neighbors (1,100 kilometers per second). Its magnetic field and wind of particles creates a visible bow shock 4 light-years ahead of it, colliding with the diffuse, and usually invisible, interstellar gas and dust. This is about the same distance that we are from Proxima Centauri, the nearest star to the sun.[3] [4]


  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:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. ^ a b c d e Crowther, P. A.; Lennon, D. J.; Walborn, N. R. (January 2006), "Physical parameters and wind properties of galactic early B supergiants", Astronomy and Astrophysics 446 (1): 279–293, arXiv:astro-ph/0509436, Bibcode:2006A&A...446..279C, doi:10.1051/0004-6361:20053685 
  3. ^ Clavin, Whitney. "The bow shock of Kappa Cassiopeiae, a massive, hot supergiant". Phys.org. 
  4. ^ http://www.nasa.gov/jpl/spitzer/bow-shock-wave-20140220/#.Uwd-BVNfQpQ