24 Cephei

24 Cephei
Observation data
Epoch J2000      Equinox J2000
Constellation Cepheus
Right ascension 22h 09m 48.43010s[1]
Declination +72° 20′ 28.3421″[1]
Apparent magnitude (V) 4.79[2]
Characteristics
Spectral type G7 II-III[3]
B−V color index 0.898[4]
Astrometry
Radial velocity (Rv)−16.58[4] km/s
Proper motion (μ) RA: +33.214[1] mas/yr
Dec.: +2.679[1] mas/yr
Parallax (π)8.3965 ± 0.1332 mas[1]
Distance388 ± 6 ly
(119 ± 2 pc)
Absolute magnitude (MV)−0.519[4]
Details
Mass3.50[5] M☉
Radius13[6] R☉
Luminosity209[5] L☉
Surface gravity (log g)2.31±0.33[7] cgs
Temperature5,023±54[7] K
Metallicity [Fe/H]−0.16±0.11[7] dex
Rotational velocity (v sin i)6.5[8] km/s
Age234[5] Myr
Other designations
24 Cep, BD+71° 1111, FK5 837, HD 210807, HIP 109400, HR 8468, SAO 10265[9]
Database references
SIMBADdata

24 Cephei is a single,[10] yellow-hued star in the northern circumpolar constellation of Cepheus. With an apparent visual magnitude of 4.79,[2] it is faintly visible to the naked eye. The distance to this star, based upon an annual parallax shift of 8.3965 mas,[1] is around 388 light years. It is moving closer with a heliocentric radial velocity of −17 km/s.[4]

Keenan and McNeil (1989) listed a stellar classification of G7 II-III[3] for 24 Cep, matching the spectrum of an evolved G-type star with blended features of a bright giant and a giant star. Older sources list a class of G8 III,[11] which would suggest an ordinary giant star. At the age of 234 million years,[5] it has an estimated 3.5[5] times the mass of the Sun and has expanded to about 13[6] times the Sun's radius. The star is radiating 199[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,023 K.[7] These coordinates are a source of X-ray emission.[12]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Soubiran2008 was invoked but never defined (see the help page).
  5. ^ a b c d e Cite error: The named reference Takeda2008 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference CADARS was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Koleva2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Lebre2006 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Roman1952 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Haakonsen2009 was invoked but never defined (see the help page).