Astronomy:Xi Cygni
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 04m 55.8599s[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 mas/yr |
| Parallax (π) | 2.8363 ± 0.1269[1] mas |
| Distance | 1,150 ± 50 ly (350 ± 20 pc) |
| 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☉ |
| 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[5] M☉ |
| Other designations | |
| 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).[1] At this distance, the apparent magnitude is diminished by 0.16 magnitudes from interstellar dust.[6]
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.[5]
ξ Cygni is in the Kepler spacecraft's field of view but no planets have been detected.[7]
Gallery
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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
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 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.
- ↑ 3.0 3.1 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. doi:10.1086/342942. Bibcode: 2002ApJS..143..513G.
- ↑ 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, doi:10.1051/0004-6361:20041272, Bibcode: 2005A&A...430..165F
- ↑ 5.0 5.1 5.2 5.3 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.
- ↑ 6.0 6.1 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. doi:10.3847/1538-3881/ac2431. ISSN 0004-6256. Bibcode: 2021AJ....162..198B.
- ↑ 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. doi:10.1093/mnras/stt1095. Bibcode: 2013MNRAS.434.1422M.
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