20 Cygni

20 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 50m 37.72371s[1]
Declination +52° 59′ 16.7901″[1]
Apparent magnitude (V) 5.030[2]
Characteristics
Spectral type K3 III CN2[3]
B−V color index 1.280[2]
Astrometry
Radial velocity (Rv)−22.04±0.15[4] km/s
Proper motion (μ) RA: −10.29[1] mas/yr
Dec.: −69.68[1] mas/yr
Parallax (π)16.11 ± 0.14 mas[1]
Distance202 ± 2 ly
(62.1 ± 0.5 pc)
Details
Mass1.28[2] M☉
Radius13[5] R☉
Luminosity57.5[2] L☉
Surface gravity (log g)2.2[5] cgs
Temperature4,337±67[2] K
Metallicity [Fe/H]+0.14[5] dex
Rotational velocity (v sin i)4.6[5] km/s
Other designations
d Cyg, 20 Cyg, BD+52°2547, FK5 3586, HD 188056, HIP 97635, HR 7576, SAO 32042[6]
Database references
SIMBADdata

20 Cygni is a single,[7] orange-hued star in the northern constellation of Cygnus. It is a faint star but is visible to the naked eye with an apparent visual magnitude of 5.03.[2] The distance to 20 Cygni can be estimated from its annual parallax shift of 16 mas,[1] which yields a range of 202 light years. It is moving closer to the Earth with a heliocentric radial velocity of −22 km/s.[4]

This is an aging red giant star with a stellar classification of K3 III CN2,[3] a star that has used up its core hydrogen and is expanding. The suffix notation indicates there are unusually strong lines of cyanogen in the spectrum. 20 Cyg is listed as one of the least variable stars in the Hipparcos catalogue, changing its brightness by no more than 0.01 magnitude.[8] It has 1.28[2] times the mass of the Sun and has expanded to 13[5] times the Sun's radius. The star is radiating 57.5 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,337 K.[2]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Luck2015 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 Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  5. ^ a b c d e Cite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Adelman2001 was invoked but never defined (see the help page).