Xi Cygni

Xi Cygni
	Location of ξ Cygni (circled)
Observation data; Epoch J2000 Equinox ICRS
Constellation	Cygnus
Right ascension	21h 04m 55.8599s
Declination	+43° 55′ 40.272″
Apparent magnitude (V)	3.73
Characteristics
Spectral type	K4:Ib- + A1.5V
U−B color index	+1.78
B−V color index	+1.66
Astrometry
Radial velocity (Rv)	−19.10 km/s
Proper motion (μ)	RA: +10.062 mas/yr ; Dec.: +0.861 mas/yr
Parallax (π)	2.8363±0.1269 mas
Distance	1,150 ± 50 ly ; (350 ± 20 pc)
Absolute magnitude (MV)	−4.3/+1.3
Orbit
Period (P)	6,750 ± 200 days
Semi-major axis (a)	~766 R☉
Eccentricity (e)	0.25 ± 0.07
Inclination (i)	~50°
Details
Primary
Mass	~8 M☉
Radius	220.09+9.64; −10.56 R☉
Luminosity	9889±964 L☉
Surface gravity (log g)	0.89 cgs
Temperature	3,878±33 – 4,031 K
Metallicity [Fe/H]	−0.26 dex
Secondary
Mass	~2.5 M☉
Other designations
	ξ Cyg, 62 Cygni, FK5 792, GC 29459, HD 200905, HIP 104060, HR 8079, SAO 50424
Database references
SIMBAD	data

Xi Cygni is a binary star system in the constellation Cygnus. Its name is a Bayer designation that is Latinized from ξ Cygni and abbreviated Xi Cyg or ξ Cyg. The pair have a combined apparent visual magnitude of 3.73, making it readily visible to the naked eye as a point of light. Based on parallax measurements, the system is located at a distance of 350 parsecs (1,100 ly). At this distance, the apparent magnitude is diminished by 0.16 magnitudes from interstellar dust.

This spectroscopic binary system contains two stars which orbit every 18 years in a moderately eccentric orbit. The primary star is a supergiant with a spectral type of around K4, while the secondary is an A-type main-sequence star with a spectral type of A1.5. Stellar winds from the supergiant have been measured at around 50 km/s, but with variations in speed and individual line strengths.

ξ Cygni is in the Kepler spacecraft's field of view but no planets have been detected.

Gallery

H-alpha RGB amateur image of ξ Cygni, center star, at edge of NGC7000
NGC 7000 (North America Nebula). ξ Cygni is the bright star on the left.

References

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.
1 2 3 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
1 2 Ginestet, N.; Carquillat, J. M. (2002). "Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components". The Astrophysical Journal Supplement Series. 143 (2): 513. Bibcode:2002ApJS..143..513G. doi:10.1086/342942.
↑ Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304
1 2 3 4 Reimers, D.; Schroeder, K.-P. (1989). "Observations of modulation and phase displacement of the stellar wind in six red giant spectroscopic binaries". Astronomy and Astrophysics. 214: 261. Bibcode:1989A&A...214..261R.
1 2 Baines, Ellyn K.; et al. (2021-10-15). "Angular Diameters and Fundamental Parameters of Forty-four Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 162 (5): 198. arXiv:2211.09030. Bibcode:2021AJ....162..198B. doi:10.3847/1538-3881/ac2431. ISSN 0004-6256.
↑ Molenda-Żakowicz, J.; et al. (2013). "Atmospheric parameters of 169 F-, G-, K- and M-type stars in the Kepler field". Monthly Notices of the Royal Astronomical Society. 434 (2): 1422. arXiv:1306.6011. Bibcode:2013MNRAS.434.1422M. doi:10.1093/mnras/stt1095. S2CID 59269553.

[dr3-1] 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.

[Ducati2002-2] 1 2 3 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.

[ginestat-3] 1 2 Ginestet, N.; Carquillat, J. M. (2002). "Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components". The Astrophysical Journal Supplement Series. 143 (2): 513. Bibcode:2002ApJS..143..513G. doi:10.1086/342942.

[Famaey2005-4] Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304

[reimers-5] 1 2 3 4 Reimers, D.; Schroeder, K.-P. (1989). "Observations of modulation and phase displacement of the stellar wind in six red giant spectroscopic binaries". Astronomy and Astrophysics. 214: 261. Bibcode:1989A&A...214..261R.

[baines-6] 1 2 Baines, Ellyn K.; et al. (2021-10-15). "Angular Diameters and Fundamental Parameters of Forty-four Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 162 (5): 198. arXiv:2211.09030. Bibcode:2021AJ....162..198B. doi:10.3847/1538-3881/ac2431. ISSN 0004-6256.

[mz-7] Molenda-Żakowicz, J.; et al. (2013). "Atmospheric parameters of 169 F-, G-, K- and M-type stars in the Kepler field". Monthly Notices of the Royal Astronomical Society. 434 (2): 1422. arXiv:1306.6011. Bibcode:2013MNRAS.434.1422M. doi:10.1093/mnras/stt1095. S2CID 59269553.