Astronomy:26 Cygni
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 01m 21.56485s[1] |
| Declination | +50° 06′ 16.8912″[1] |
| Apparent magnitude (V) | 5.12[2] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | G8 III[3] |
| B−V color index | 1.122[4] |
| Astrometry | |
| Radial velocity (Rv) | −0.25±0.16[1] km/s |
| Proper motion (μ) | RA: +15.520[1] mas/yr Dec.: +5.805[1] mas/yr |
| Parallax (π) | 7.2271 ± 0.0853[1] mas |
| Distance | 451 ± 5 ly (138 ± 2 pc) |
| Absolute magnitude (MV) | −0.56[5] |
| Details | |
| Mass | 2.44[6] M☉ |
| Radius | 22.27[6] R☉ |
| Luminosity | 204.8[6] L☉ |
| Surface gravity (log g) | 2.50[4] cgs |
| Temperature | 4,700[4] K |
| Metallicity [Fe/H] | −0.09±0.04[5] dex |
| Rotational velocity (v sin i) | 3.63[4] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
26 Cygni is a single[8] star in the northern constellation of Cygnus. It has the Bayer designation e Cygni, while 26 Cygni is the Flamsteed designation. This star is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of 5.12.[2] It is located around 451 light-years (138 pc) distant from the Sun,[1] based on parallax measurements. The radial velocity is close to negligible, being measured at −0.3 km/s.[1]
This object is an evolved giant star with a stellar classification of G8 III;[3] a star that has used up its core hydrogen and left the main sequence. It is most likely (88% chance) on the horizontal branch, in which case stellar modelling yields an estimated 2.44 times the mass of the Sun and 22 times the Sun's radius.[6] It is radiating 205[6] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,700 K.[4]
There is a magnitude 8.94 visual companion at an angular separation of 41.6″ along a position angle of 150°, as of 2014.[9]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 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 Fernie, J. D. (1983). "New UBVRI photometry for 900 supergiants". Astrophysical Journal Supplement Series 52: 7. doi:10.1086/190856. Bibcode: 1983ApJS...52....7F.
- ↑ 3.0 3.1 Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series 176 (1): 216–217. doi:10.1086/525529. Bibcode: 2008ApJS..176..216A.
- ↑ 4.0 4.1 4.2 4.3 4.4 Hekker, S.; Meléndez, J. (2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics 475 (3): 1003. doi:10.1051/0004-6361:20078233. Bibcode: 2007A&A...475.1003H.
- ↑ 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 6.2 6.3 6.4 Stock, Stephan et al. (August 2018). "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search". Astronomy & Astrophysics 616: 15. doi:10.1051/0004-6361/201833111. A33. Bibcode: 2018A&A...616A..33S.
- ↑ "26 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=26+Cyg.
- ↑ 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.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22
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