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 | asymptotic giant branch[3] |
| Spectral type | M1IIIab[4] |
| B−V color index | 1.601±0.006[2] |
| Variable type | suspected[5] |
| 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 | |
| Mass | 1.4[6] M☉ |
| Radius | 46[7] R☉ |
| Luminosity | 442[7] L☉ |
| Surface gravity (log g) | 1.69[6] cgs |
| Temperature | 3,906[7] K |
| Metallicity [Fe/H] | −0.24[6] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
75 Cygni is a binary star[9] 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.[9] The brighter magnitude 5.18[9] primary is an aging red giant star with a stellar classification of M1IIIab.[4] Having exhausted the supply of hydrogen at its core, it has expanded to around 46 times the radius of the Sun.[7] It is a suspected variable star of unknown type and amplitude.[5] The star is radiating 442 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,906 K.[7]
It is likely that 75 Cygni is on the asymptotic giant branch, having exhausted its core helium,[3] but there is a chance that it might be a higher-mass star on the red giant branch, before igniting its core helium.[10]
An optical companion, with a spectral type of K, is about an arcminute away and has an apparent magnitude of 10.14.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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 Eggen, Olin J. (1992), "Asymptotic Giant Branch Stars Near the Sun", The Astronomical Journal 104: 275, doi:10.1086/116239, Bibcode: 1992AJ....104..275E.
- ↑ 4.0 4.1 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.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 6.2 Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G. et al. (2024), "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost", Astronomy and Astrophysics 691: A98, doi:10.1051/0004-6361/202451427, Bibcode: 2024A&A...691A..98K.
- ↑ 7.0 7.1 7.2 7.3 7.4 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel et al. (2023), "Variability Catalog of Stars Observed during the TESS Prime Mission", The Astrophysical Journal Supplement Series 268 (1): 4, doi:10.3847/1538-4365/acdee5, Bibcode: 2023ApJS..268....4F.
- ↑ "75 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=75+Cyg.
- ↑ 9.0 9.1 9.2 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.
- ↑ 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.
- ↑ "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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