Xi Cygni

(Redirected from Ξ Cygni)

ξ Cygni (Latinised as Xi Cygni) is a spectroscopic binary star in the constellation Cygnus, made up of a K-type supergiant star (primary) and an A-type star (secondary). Its apparent magnitude is 3.73, making it readily visible to the naked eye, and it is located around 350 parsecs (1,100 ly) away.

ξ Cygni
Location of ξ Cygni (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 21h 04m 55.86s[1]
Declination +43° 55′ 40.272″[1]
Apparent magnitude (V) 3.73[2]
Characteristics
Spectral type K4:Ib- + A1.5V[3]
U−B color index +1.78[2]
B−V color index +1.66[2]
Astrometry
Radial velocity (Rv)-19.10[4] km/s
Proper motion (μ) RA: +10.062[1] mas/yr
Dec.: +0.861[1] mas/yr
Parallax (π)2.8363 ± 0.1269 mas[1]
Distance1,150 ± 50 ly
(350 ± 20 pc)[1]
Absolute magnitude (MV)−4.3/+1.3[3]
Orbit[5]
Period (P)6,750 ± 200 days
Semi-major axis (a)~766 R
Eccentricity (e)0.25 ± 0.07
Inclination (i)~50°
Details[6]
Primary
Mass~8[5] M
Radius220.09+9.64
−10.56
 R
Luminosity9889±964 L
Surface gravity (log g)0.89 cgs
Temperature3,878±33 – 4,031 K
Metallicity [Fe/H]−0.26 dex
Secondary
Mass~2.5[5] M
Other designations
62 Cygni, FK5 792, GC 29459, HIP 104060, HR 8079, HD 200905, SAO 50424
Database references
SIMBADdata

Characteristics

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The system contains two stars which orbit every 18 years in a mildly 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.[5]

The distance to Xi Cygni is of about 350 parsecs (1,100 ly), based on parallax measurements.[1] At this distance, the apparent magnitude is diminished by 0.16 magnitudes.[6]

ξ Cygni is in the Kepler spacecraft's field of view but no planets have been detected.[7]

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References

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  1. ^ a b c d e f g 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.
  2. ^ a b c 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: 0. Bibcode:2002yCat.2237....0D.
  3. ^ a b 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.
  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
  5. ^ a b c d 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.
  6. ^ a b Baines, Ellyn K.; Thomas Armstrong, J.; Clark, James H.; Gorney, Jim; Hutter, Donald J.; Jorgensen, Anders M.; Kyte, Casey; Mozurkewich, David; Nisley, Ishara; Sanborn, Jason; Schmitt, Henrique R.; van Belle, Gerard T. (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.
  7. ^ Molenda-Żakowicz, J.; Sousa, S. G.; Frasca, A.; Uytterhoeven, K.; Briquet, M.; Van Winckel, H.; Drobek, D.; Niemczura, E.; Lampens, P.; Lykke, J.; Bloemen, S.; Gameiro, J. F.; Jean, C.; Volpi, D.; Gorlova, N.; Mortier, A.; Tsantaki, M.; Raskin, G. (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.