74 Cygni

74 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 21h 36m 56.97051s[1]
Declination +40° 25′ 48.5818″[1]
Apparent magnitude (V) 5.04[2]
Characteristics
Evolutionary stage main sequence[3]
Spectral type A3 Vn[4]
B−V color index 0.198±0.003[2]
Astrometry
Radial velocity (Rv)5.3±2.9 km/s
Proper motion (μ) RA: +2.270[1] mas/yr
Dec.: +18.399[1] mas/yr
Parallax (π)13.0909 ± 0.2893 mas[1]
Distance249 ± 6 ly
(76 ± 2 pc)
Absolute magnitude (MV)0.95[2]
Orbit[5]
Period (P)574.632±9.4158 d
Semi-major axis (a)8.56±0.91 mas
Eccentricity (e)0.5349±0.1066
Inclination (i)102.1±4.39°
Longitude of the node (Ω)18.92°
Periastron epoch (T)8579.5387±18.6175
Argument of periastron (ω)
(secondary)		306.56±14.01°
Details
74 Cyg A
Mass1.68[6] M☉
Radius1.6[7] R☉
Luminosity35.64[2] L☉
Surface gravity (log g)3.89[6] cgs
Temperature7,859±267[6] K
Rotational velocity (v sin i)201[3] km/s
Age606[6] Myr
Other designations
74 Cyg, BD+39°4612, FK5 811, HD 205835, HIP 106711, HR 8266, SAO 51101, WDS J21369+4025[8]
Database references
SIMBADdata

74 Cygni is a visual binary[9] star system in the northern constellation Cygnus, located around 249 light years distant from the Sun. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.04.[2] The pair orbit each other with a period of 1.57 years and an eccentricity of 0.5.[5] The system is a source of X-ray emission, which is most likely coming from the secondary component.[10]

The primary component is an A-type main-sequence star with a stellar classification of A3 Vn;[4] a star that is fusing its core hydrogen. The 'n' suffix indicates "nebulous" absorption lines due to rapid rotation, with the star having a projected rotational velocity of 201 km/s.[3] The high rate of spin is giving the star an oblate shape with an equatorial bulge that is 8% larger than the polar radius.[11] The star has 1.68[6] times the mass of the Sun and is radiating 36[2] times the Sun's luminosity from its photosphere at an effective temperature of about 7,859 K.[6]

  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 e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference abt1995 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference ESA1997 was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference David2015 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Fracassini2001 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Schröder2007 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference vanBelle2012 was invoked but never defined (see the help page).