71 Cygni

71 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 21h 29m 26.94995s[1]
Declination +46° 32′ 26.1024″[1]
Apparent magnitude (V) 5.22[2]
Characteristics
Spectral type K0− III[3]
B−V color index 0.965±0.004[2]
Astrometry
Radial velocity (Rv)−21.54±0.10[4] km/s
Proper motion (μ) RA: +43.048[1] mas/yr
Dec.: +104.683[1] mas/yr
Parallax (π)15.4057 ± 0.1077 mas[1]
Distance212 ± 1 ly
(64.9 ± 0.5 pc)
Absolute magnitude (MV)1.11[2]
Details[4]
Mass2.05±0.09 M☉
Radius8.31±0.32 R☉
Luminosity44.7+7.8
−6.7 L☉
Surface gravity (log g)3.03±0.05 cgs
Temperature4,983±18 K
Metallicity [Fe/H]0.05±0.06 dex
Rotational velocity (v sin i)2.03±0.85 km/s
Age1.07±0.15 Gyr
Other designations
g Cyg, 71 Cyg, BD+45°3558, FK5 807, HD 204771, HIP 106093, HR 8228, SAO 50934[5]
Database references
SIMBADdata

71 Cygni is a star in the northern constellation of Cygnus, located 212 light years from the Sun.[1] 71 Cygni is the Flamsteed designation; it has the Bayer designation g Cygni.[5] It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.22.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −21.5 km/s.[4]

At the age of one billion years,[4] this is an evolved giant star with a stellar classification of K0− III,[3] which means it has used up its core hydrogen and expanded. It is a red clump giant, indicating that it is on the horizontal branch of the Hertzsprung–Russell diagram and is generating energy by helium fusion at its center.[6][7] The star has double the mass of the Sun and eight times the Sun's radius. It is radiating 45 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,983 K.[4]

  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 d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference perkins1989 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference jofre2015 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Mishenina2006 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Valentini2010 was invoked but never defined (see the help page).