Zeta Cephei

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Zeta Cephei
Observation data
Epoch J2000
Constellation
(pronunciation)
Cepheus
Right ascension 22h 10m 51.2s
Declination +58° 12′ 05.0″
Apparent magnitude (V) 3.39
Characteristics
Spectral type K1 IV
Variable type Suspected
Astrometry
Parallax (π) 4.49 mas
Distance 726.40619153675 ly
(222.71714922049 pc)
Details
Mass 7.9 M
Radius 110.0 R
Luminosity 3600 L
Temperature 4,310 K
Rotation 8 km/s.
Age 50 million years years
Other designations
Tsao Fu, 21 Cephei, HR 8465, BD +57°2475, HD 210745, GCTP 5139.00, SAO 84137, FK5 836, HIP 105199.

Zeta Cephei (ζ Cep / ζ Cephei) is a star in the constellation of Cepheus. Zeta Cephei marks the left shoulder of Cepheus the King of Joppa (Ethiopia). There is no regularly used proper name for Zeta Cephei, but one possible proper name for the star is Tsao Fu, which was the name of a great charioteer in Chinese mythology, that was imagined among the stars of the constellation Cepheus by the Chinese.

Zeta Cephei is by nature an orange subgiant star of spectral type K1 IV, with a surface temperature of 4,310 kelvins and eight times more massive then the Sun. The luminosity of Zeta Cephei is approximately 3600 times that of the Sun. At a distance of about 726 light-years, Zeta Cephei has an apparent magnitude (m) of 3.39 and an absoltute magnitude (M) of -3.35. The star has a metallicity approximately 1.6 times that of the Sun; i.e., it contains 1.6 times as much heavy-element material as the sun. At the edge of the 8 to 10 solar mass limit at which stars develop iron cores and then explode as supernovae, Zeta Cephei's most likely fate is to produce a very massive white dwarf near the Chandrasekhar limit (1.4 solar mass) at which such dense remnants can survive. If Zeta Cephei is a binary star; i.e., if there is a stellar companion, and it is close enough to feed sufficient matter to the white-dwarf-to-be, it is marginally possible that the limit could be overflowed, resulting in the white dwarf's collapse and a Type Ia supernova explosion.

[edit] External Links and References

  • [1] by Jim Kaler
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