7 Cephei

7 Cephei
Observation data
Epoch J2000      Equinox J2000
Constellation Cepheus
Right ascension 21h 27m 46.14144s[1]
Declination +66° 48′ 32.7406″[1]
Apparent magnitude (V) 5.42[2]
Characteristics
Evolutionary stage main sequence[3]
Spectral type B7 V[4]
B−V color index −0.099±0.004[2]
Astrometry
Radial velocity (Rv)+3.0±4.2[5] km/s
Proper motion (μ) RA: −11.296[1] mas/yr
Dec.: −19.787[1] mas/yr
Parallax (π)3.9653 ± 0.1148 mas[1]
Distance820 ± 20 ly
(252 ± 7 pc)
Absolute magnitude (MV)−1.54[2]
Details
Mass4.47±0.07[3] M☉
Radius3.0[6] R☉
Luminosity769+94
−84[3] L☉
Surface gravity (log g)3.56[7] cgs
Temperature12,560+87
−86[3] K
Metallicity [Fe/H]−0.36[7] dex
Rotational velocity (v sin i)236[3] km/s
Age38[8] Myr
Other designations
7 Cep, BD+66°1405, FK5 3718, HD 204770, HIP 105972, HR 8227, SAO 19432[9]
Database references
SIMBADdata

7 Cephei is a single[10] star located approximately 820 light years away, in the northern circumpolar constellation of Cepheus. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.42.[2]

This is a B-type main-sequence star with a stellar classification of B7 V.[4] It is a candidate variable star with an amplitude of 9 micromagnitudes and a period of 0.737±0.002 d.[11] This object has 4.5[3] times the mass of the Sun and about three[6] times the Sun's radius. It is spinning rapidly with a projected rotational velocity of 236 km/s.[3] 7 Cephei is radiating 769[3] times the luminosity of the Sun from its photosphere at an effective temperature of 12,560 K.[3]

  1. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h i Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Lesh1968 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Niemczura2003 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference gullikson2016 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 Burggraaff2018 was invoked but never defined (see the help page).