22 Cygni

22 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 55m 51.75718s[1]
Declination +38° 29′ 12.154″[1]
Apparent magnitude (V) 4.95[2]
Characteristics
Spectral type B5 IV[3]
B−V color index −0.086±0.009[2]
Astrometry
Radial velocity (Rv)−14.8±2.2[4] km/s
Proper motion (μ) RA: +6.559[1] mas/yr
Dec.: −0.469[1] mas/yr
Parallax (π)3.0418 ± 0.2388 mas[1]
Distance1,070 ± 80 ly
(330 ± 30 pc)
Absolute magnitude (MV)−3.18[2]
Orbit[5]
Period (P)78.2±0.4 d
Eccentricity (e)0.17±0.13
Periastron epoch (T)2443734.5±2.1 JD
Argument of periastron (ω)
(secondary)		139±11°
Semi-amplitude (K1)
(primary)		20.7±3.1 km/s
Details
22 Cyg A
Mass7.9±0.4[6] M☉
Radius5.6[7] R☉
Luminosity7,305[8] L☉
Surface gravity (log g)3.35[9] cgs
Temperature15,200[8] K
Rotational velocity (v sin i)30[10] km/s
Age37.3±4.2[6] Myr
Other designations
22 Cyg, BD+38°3817, HD 188892, HIP 98068, HR 7613, SAO 69101[11]
Database references
SIMBADdata

22 Cygni is a binary star system in the northern constellation of Cygnus. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.95.[2] The annual shift of 3.0 mas[1] yields a distance estimate of around 1,070 light years. It is moving closer to the Earth with a heliocentric radial velocity of −15 km/s.[4]

This is a single-lined spectroscopic binary with an orbital period of 78.2 days and an eccentricity of roughly 0.17.[5] The visible component has a stellar classification of B5 IV[3] that matches a B-type subgiant star. It is 37[6] million years old with a projected rotational velocity of 30[10] km/s and has an essentially solar metallicity, within the margin of error.[9] The star has eight[6] times the mass of the Sun and about 5.6[7] times the Sun's radius. It is radiating 7,305[8] times the Sun's luminosity from its photosphere at an effective temperature of 15,200 K.[8]

  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 Lesh1968 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Abt1990 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Fracassini2001 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Adelman1998 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).