| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 33m 15.07905s[1] |
| Declination | +41° 18′ 50.4762″[1] |
| Apparent magnitude (V) | 9.06[2] |
| Characteristics | |
| Spectral type | O6If + O5.5III(f)[3] |
| U−B color index | +0.15[4] |
| B−V color index | +1.29[4] |
| Astrometry | |
| Radial velocity (Rv) | 125.56[5] km/s |
| Proper motion (μ) | RA: −2.664[5] mas/yr Dec.: −4.895[5] mas/yr |
| Parallax (π) | 0.6058 ± 0.0191 mas[5] |
| Distance | 5,400 ± 200 ly (1,650 ± 50 pc) |
| Absolute magnitude (MV) | −6.78[6] |
| Orbit[7] | |
| Period (P) | 21.9 days |
| Semi-major axis (a) | 71 R☉[8] |
| Eccentricity (e) | 0.24 |
| Semi-amplitude (K1) (primary) | 82.8 km/s |
| Semi-amplitude (K2) (secondary) | 95.8 km/s |
| Details[8] | |
| Cyg OB2 #8A1 | |
| Mass | 44.1 M☉ |
| Radius | 20 R☉ |
| Luminosity | 650,000 L☉ |
| Surface gravity (log g) | 3.48 cgs |
| Temperature | 36,800 K |
| Cyg OB2 #8A2 | |
| Mass | 37.4 M☉ |
| Radius | 14.8 R☉ |
| Luminosity | 468,000 L☉ |
| Surface gravity (log g) | 3.67 cgs |
| Temperature | 39,200 K |
| Age | 2[6] Myr |
| Other designations | |
Schulte 8A, 1E 203127+4108.5, TYC 3161-1325-1, ADS 14000 A, 2E 4382, HIP 101425, UBV 17839, AG+41° 1925, 2E 2031.4+4108, IDS 20297+4058, LS III +41 37, Cyg OB2-8A, 1ES 2031+41.1, 2MASS J20331508+4118504, BD+40 4227, GCRV 20036, PPM 60129, CCDM J20332+4119A, 1RXS J203315.8+411848, CGO 605, GOS G080.22+00.79 01, SAO 49781, CSI+40 4227 1, GSC 03161-01325, Gaia DR2 2067784624247057920 | |
| Database references | |
| SIMBAD | data |
Cygnus OB2 #8A is a double-lined spectroscopic binary located near the centre of the Cygnus OB2 association located 5,500 light years away.
- ^ a b 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. S2CID 18759600.
- ^ Caballero-Nieves, S. M.; Nelan, E. P.; Gies, D. R.; Wallace, D. J.; Degioia-Eastwood, K.; Herrero, A.; Jao, W.-C.; Mason, B. D.; Massey, P.; Moffat, A. F. J.; Walborn, N. R. (2014). "A High Angular Resolution Survey of Massive Stars in Cygnus OB2: Results from the Hubble Space Telescope Fine Guidance Sensors". The Astronomical Journal. 147 (2): 40. arXiv:1311.5087. Bibcode:2014AJ....147...40C. doi:10.1088/0004-6256/147/2/40. S2CID 22036552.
- ^ Cazorla, Constantin; Nazé, Yaël; Rauw, Gregor (2014). "Wind collisions in three massive stars of Cygnus OB2". Astronomy & Astrophysics. 561: A92. arXiv:1312.1871. Bibcode:2014A&A...561A..92C. doi:10.1051/0004-6361/201322539. S2CID 53682076.
- ^ a b 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.
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b Negueruela, I.; Marco, A.; Herrero, A.; Clark, J. S. (2008). "New very massive stars in Cygnus OB2". Astronomy and Astrophysics. 487 (2): 575. arXiv:0806.2879. Bibcode:2008A&A...487..575N. doi:10.1051/0004-6361:200810094. S2CID 10915879.
- ^ Cite error: The named reference
debeckerwas invoked but never defined (see the help page). - ^ a b De Becker, M.; Rauw, G.; Sana, H.; Pollock, A. M. T.; Pittard, J. M.; Blomme, R.; Stevens, I. R.; Van Loo, S. (2006). "XMM-Newton observations of the massive colliding wind binary and non-thermal radio emitter CygOB2#8A [O6If + O5.5III(f)]" (PDF). Monthly Notices of the Royal Astronomical Society. 371 (3): 1280. Bibcode:2006MNRAS.371.1280D. doi:10.1111/j.1365-2966.2006.10746.x.