2 Cygni
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.
| 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[1] mas |
| Distance | 910 ± 40 ly (280 ± 10 pc) |
| Absolute magnitude (MV) | −2.06[4] |
| Details | |
| Mass | 7.0±0.1[5] M☉ |
| Radius | 5.6[6] R☉ |
| Luminosity (bolometric) | 3,354[2] L☉ |
| Surface gravity (log g) | 3.653±0.035[7] cgs |
| Temperature | 16,479±219[7] K |
| Metallicity [Fe/H] | +0.03±0.05[8] dex |
| Rotational velocity (v sin i) | 137±8[7] km/s |
| Age | 36.6±0.5[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
- 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.
- 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.
- 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.
- 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.
- 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.
- Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS", Astronomy and Astrophysics (Third ed.), 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
- 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.
- 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.
- "2 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-07.
- 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.