Psi Cygni

Psi Cygni
Location of ψ Cygni (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cygnus
Right ascension 19h 55m 37.789s
Declination +52° 26′ 20.180″
Apparent magnitude (V) 4.91 (5.05 + 7.61)
Characteristics
A
Spectral type A4 Vn
U−B color index +0.05
B−V color index +0.124±0.006
B
Spectral type F4 V
Astrometry
Radial velocity (Rv)−10 km/s
Proper motion (μ) RA: −37.044 mas/yr
Dec.: −27.970 mas/yr
Parallax (π)11.5546±0.3168 mas
Distance282 ± 8 ly
(87 ± 2 pc)
Absolute magnitude (MV)+0.23
Orbit
PrimaryAa
SecondaryAb
Period (P)54.08 yr
Semi-major axis (a)0.141″
Eccentricity (e)0.484
Inclination (i)112.0°
Details
ψ Cyg Aa
Luminosity62 L☉
Temperature7,971 K
Rotational velocity (v sin i)207 km/s
ψ Cyg B
Rotational velocity (v sin i)120 km/s
Other designations
ψ Cyg, 24 Cygni, BD+52°2572, HD 189037, HIP 98055, HR 7619, SAO 32114, WDS 19556+5226
Database references
SIMBADdata

Psi Cygni is a triple star system in the constellation of Cygnus. Its name is a Bayer designation that is Latinized from ψ Cygni and is abbreviated Psi Cyg or ψ Cyg. With a combined apparent visual magnitude of 4.92, it is visible to the naked eye as a point of light. Based upon an annual parallax shift of 11.55 mas, Psi Cygni is located at a distance of around 282 light years from the Sun.

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°. Their combined visual magnitude is 5.05. Relative to this pair, the third member of the system, magnitude 7.61 component B, had an angular separation of 2.87 arc seconds along a position angle of 175.6° as of 2010.

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, where the 'n' notation indicates "nebulous" absorption lines due to rapid rotation. It is spinning rapidly with a projected rotational velocity of 207 km/s. The component is radiating 62 times the solar luminosity from its outer atmosphere at an effective temperature of 7,971 K.

Component B has a spectral class of F4 V, matching an F-type main-sequence star. It is spinning with a high projected rotational velocity of 120 km/s.

References

  1. 1 2 3 4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  4. 1 2 3 4 Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
  5. 1 2 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, Bibcode:1986EgUBV........0M.
  6. 1 2 Edwards, T. W. (April 1976), "MK classification for visual binary components", Astronomical Journal, 81: 245–249, Bibcode:1976AJ.....81..245E, doi:10.1086/111879.
  7. ↑ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, p. 57, Bibcode:1967IAUS...30...57E.
  8. ↑ Tokovinin, Andrei (2018), "The Updated Multiple Star Catalog", The Astrophysical Journal Supplement Series, 235 (1): 6, arXiv:1712.04750, Bibcode:2018ApJS..235....6T, doi:10.3847/1538-4365/aaa1a5, S2CID 119047709.
  9. 1 2 3 McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  10. 1 2 Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, Bibcode:1970crvs.book.....U.
  11. ↑ "* psi Cyg", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-02-21.
  12. ↑ Roberts, Lewis C. Jr. (May 2011), "Astrometric and photometric measurements of binary stars with adaptive optics: observations from 2002", Monthly Notices of the Royal Astronomical Society, 413 (2): 1200–1205, arXiv:1012.3383, Bibcode:2011MNRAS.413.1200R, doi:10.1111/j.1365-2966.2011.18205.x, S2CID 118398949.
  13. ↑ Mason, Brian D.; et al. (August 2011), "Speckle Interferometry at the U.S. Naval Observatory. XVII.", The Astronomical Journal, 142 (2): 4, Bibcode:2011AJ....142...46M, doi:10.1088/0004-6256/142/2/46, S2CID 250806722, 46.