Astronomy:75 Cygni
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 40m 11.10795s[1] |
| Declination | +43° 16′ 25.8161″[1] |
| Apparent magnitude (V) | 5.09[2] |
| Characteristics | |
| Evolutionary stage | red giant |
| Spectral type | M1IIIab[3] |
| B−V color index | 1.601±0.006[2] |
| Variable type | suspected[4] |
| Astrometry | |
| Radial velocity (Rv) | −29.25±0.14[1] km/s |
| Proper motion (μ) | RA: +62.366[1] mas/yr Dec.: +15.488[1] mas/yr |
| Parallax (π) | 7.5210 ± 0.1706[1] mas |
| Distance | 434 ± 10 ly (133 ± 3 pc) |
| Absolute magnitude (MV) | −0.36[2] |
| Details | |
| Radius | 44.61+3.12 −7.77[1] R☉ |
| Luminosity | 438.5±11.5[1] L☉ |
| Temperature | 3,954+397 −131[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
75 Cygni is a binary star[6] system in the northern constellation of Cygnus. It is visible to the naked eye as a dim, reddish-hued point of light with an apparent visual magnitude of 5.09.[2] The system is located at a distance of about 434 light years from the Sun, based on parallax, and is drifting closer with a radial velocity of −29 km/s.[1]
The pair had an angular separation of 2.7″ as of 2008, with the companion having a visual magnitude of 10.7.[6] The brighter magnitude 5.18[6] primary is an aging red giant star with a stellar classification of M1IIIab.[3] Having exhausted the supply of hydrogen at its core, it has expanded to around 45[1] times the radius of the Sun. It is a suspected variable star of unknown type and amplitude.[4] The star is radiating 439[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,954 K.[1]
An optical companion, with a spectral type of K, is about an arcminute away and has an apparent magnitude of 10.14.[7]
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ 4.0 4.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, GCVS 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ "75 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=75+Cyg.
- ↑ 6.0 6.1 6.2 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ "BD+42 4177C". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=BD%2B42+4177C.
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