Deneb Kaitos (Beta Ceti)

Beta Ceti

X-ray image of Beta Ceti.

Deneb Kaitos (Beta Ceti) is the brightest star in the constellation Cetus. It stands out in an otherwise barren area south of the Square of Pegasus and northeast of Fomalhaut. Its Arabic name means the "whale's tail," while an alternative name "Diphda" (or "Dipda"), also Arabic, refers to the "first frog," where Formalhaut was the "second frog." A giant K star (almost type G), Deneb Kaitos is one of the brightest X-ray stars in the solar neighborhood. Its high-energy radiation, 2,000 times more powerful than that of the Sun, comes from a magnetically heated corona. It is believed that the X-ray activity is related to the star's advanced stage of evolution called core helium burning.


visual magnitude 2.04
absolute magnitude -0.30
spectral type K0III
surface temperature 4,800 K
luminosity 145 Lsun
radius 17 Rsun
mass 3 Msun
distance 96 light-years
position RA 00h 43m 35.35s,
Dec -17° 59' 11.9"