Psi Cygni

Psi Cygni
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cygnus
Right ascension 19h 55m 37.78622s[1]
Declination +52° 26′ 20.2116″[1]
Apparent magnitude (V) 4.92[2] (5.05 + 7.61)[3]
Characteristics
A
Spectral type A4 Vn[4]
U−B color index +0.05[2]
B−V color index +0.13[2]
B
Spectral type F4 V[5]
Astrometry
Radial velocity (Rv)−10[6] km/s
Proper motion (μ) RA: −37.62[1] mas/yr
Dec.: −31.13[1] mas/yr
Parallax (π)11.59 ± 0.38 mas[1]
Distance281 ± 9 ly
(86 ± 3 pc)
Absolute magnitude (MV)+0.23[7]
Orbit[8]
PrimaryAa
CompanionAb
Period (P)54.08 yr
Semi-major axis (a)0.141″
Eccentricity (e)0.484
Inclination (i)112.0°
Details
ψ Cyg Aa
Luminosity62[9] L☉
Temperature7,971[9] K
Rotational velocity (v sin i)207[4] km/s
ψ Cyg B
Rotational velocity (v sin i)120[10] km/s
Other designations
ψ Cyg, 24 Cygni, BD+52° 2572, HD 189037, HIP 98055, HR 7619, SAO 32114, WDS 19556+5226.[11]
Database references
SIMBADdata

ψ Cygni, Latinised as Psi Cygni, is a triple star[3] system in the constellation called Cygnus. With a combined apparent visual magnitude of 4.92,[2] it is visible to the naked eye. As of 2002, the inner pair, components Aa and Ab, had an angular separation of 0.10 arc seconds along a position angle of 77.6°.[12] Their combined visual magnitude is 5.05.[3] Relative to this pair, the third member of the system, magnitude 7.61[3] component B, had an angular separation of 2.87 arc seconds along a position angle of 175.6° as of 2010.[13] Based upon an annual parallax shift of 11.59 mas,[1] Psi Cygni is located around 281 light years from the Sun.

The brighter member of the system, presumably component Aa, displays the spectrum of an A-type main sequence star with a stellar classification of A4 Vn,[4] where the 'n' notation indicates "nebulous" absorption lines due to rapid rotation. It appears to be a spinning with a projected rotational velocity of 207.[4] The component is radiating 62 times the solar luminosity from its outer atmosphere at an effective temperature of 7,971 K.[9]

  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 Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Edwards1976 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference tokovinin was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference uesugi_fukuda70 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).
  12. ^ Cite error: The named reference Roberts2011 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Mason2011 was invoked but never defined (see the help page).