Mu Cygni

Mu Cygni

Observation data Epoch J2000      Equinox J2000
Constellation	Cygnus
Right ascension	21^h 44^m 08.57793^s [1]
Declination	28° 44′ 33.4731″ [1]
Apparent magnitude (V)	4.50 [2]
Characteristics
Spectral type	F6V+G2V [3]
B−V color index	+0.47 [2]
Astrometry
Radial velocity (Rv)	+16.95[4] km/s
Proper motion (μ)	RA: +260.72[2] mas/yr Dec.: -243.21[2] mas/yr
Parallax (π)	44.97 ± 0.43[1] mas
Distance	72.5 ± 0.7 ly (22.2 ± 0.2 pc)
Absolute magnitude (MV)	2.76 [5]
Other designations
78 Cygni, CCDM J21442+2845AB, HIP 107310, HR 8309, HD 206826, WDS J21441+2845AB [2]
Database references
SIMBAD	data

Mu Cygni is a binary star^[6] in the constellation Cygnus. Located around 22.24 parsecs (72.5 ly) distant, the system has a combined apparent magnitude of 4.50.^[2] The primary, with an apparent magnitude of 4.69, has a spectral type of F6V,^[7] and the secondary, with an apparent magnitude of 6.12, has a spectral type of G2V.^[8] Their orbit has a period of around 700 years, with a semimajor axis of 5" and an eccentricity around 0.6.^[9] Two reported additional components, C (apparent magnitude 12.93) and D (type A5 and apparent magnitude 6.94), are believed to be optical doubles rather than part of the Mu Cygni system.^[3]

References

1. van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
2. "CCDM J21442+2845AB". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 2016-04-08.
3. Mason, Brian D.; et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920 Vizier catalog entry
4. Maldonado, J.; Martínez-Arnáiz, R. M.; Eiroa, C.; Montes, D.; Montesinos, B. (October 2010), "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups", Astronomy and Astrophysics, 521: A12, arXiv:1007.1132, Bibcode:2010A&A...521A..12M, doi:10.1051/0004-6361/201014948
5. Absolute magnitude calculated as $M = m + 5 (1 + \log_{10}{p})\!\,$, where $M$ is the star's absolute magnitude, $m$ is the star's apparent magnitude, and $p$ is the star's measured parallax in arcseconds.
6. Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. Vizier catalog entry
7. "HR 8309". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 13 January 2014.
8. "HR 8310". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 13 January 2014.
9. Malkov, O. Yu.; et al. (October 2012), "Dynamical masses of a selected sample of orbital binaries", Astronomy & Astrophysics, 546 (A69), Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774 Vizier catalog entry