2 Cygni is a blue-white hued star in the northern constellation of Cygnus, located a few degrees from Albireo. It is a probable astrometric binary;[10] the visible component can be viewed with the naked eye, having an apparent visual magnitude of 4.976.[2] Based upon an annual parallax shift of 3.6 mas,[1] it is located roughly 910 light years from Earth. It has a peculiar velocity of 23 km/s and may be a runaway star[5] system.

2 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 24m 07.57863s[1]
Declination +29° 37′ 16.7934″[1]
Apparent magnitude (V) 4.976[2]
Characteristics
Spectral type B3 IV[3]
B−V color index −0.117[2]
Astrometry
Radial velocity (Rv)−23.60±2.0[4] km/s
Proper motion (μ) RA: +12.022[1] mas/yr
Dec.: +12.173[1] mas/yr
Parallax (π)3.5657 ± 0.1692 mas[1]
Distance910 ± 40 ly
(280 ± 10 pc)
Absolute magnitude (MV)−2.06[4]
Details
Mass7.0±0.1[5] M
Radius5.6[6] R
Luminosity (bolometric)3,354[2] L
Surface gravity (log g)3.653±0.035[7] cgs
Temperature16,479±219[7] K
Metallicity [Fe/H]+0.03±0.05[8] dex
Rotational velocity (v sin i)137±8[7] km/s
Age36.6±0.5[5] Myr
Other designations
BD+29°3584, FK5 3550, GC 26785, HD 182568, HIP 95372, HR 7372, SAO 87159[9]
Database references
SIMBADdata

The stellar classification of the primary is B3 IV,[3] matching a B-type subgiant star. It has seven[5] times the mass of the Sun and about 5.6[6] times the Sun's radius. The star is 37[5] million years old with a high rate of spin; it has a projected rotational velocity of 137 km/s.[7] It is radiating 3,354[2] times the Sun's luminosity from its photosphere at an effective temperature of 16,479 K.[7]

References

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  1. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
  3. ^ a b Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi:10.1086/190179.
  4. ^ a b 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, S2CID 119257644.
  5. ^ a b c d e Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  6. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS", Astronomy and Astrophysics, 367 (2) (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  7. ^ a b c d e Huang, W.; Gies, D. R. (August 2008), "Stellar Rotation in Field and Cluster B Stars", The Astrophysical Journal, 683 (2): 1045–1051, arXiv:0805.2133, Bibcode:2008ApJ...683.1045H, doi:10.1086/590106, S2CID 18926523.
  8. ^ Gáspár, András; et al. (2016), "The Correlation between Metallicity and Debris Disk Mass", The Astrophysical Journal, 826 (2): 171, arXiv:1604.07403, Bibcode:2016ApJ...826..171G, doi:10.3847/0004-637x/826/2/171, S2CID 119241004.
  9. ^ "2 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-07.
  10. ^ 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.