| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20 01 21.56485 |
| Declination | +50° 06′ 16.8912″ |
| Apparent magnitude (V) | 5.12 |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | G8 III |
| B−V color index | 1.122 |
| Astrometry | |
| Radial velocity (Rv) | −0.25±0.16 km/s |
| Proper motion (μ) | RA: +15.520 mas/yr Dec.: +5.805 mas/yr |
| Parallax (π) | 7.2271 ± 0.0853 mas |
| Distance | 451 ± 5 ly (138 ± 2 pc) |
| Absolute magnitude (MV) | −0.56 |
| Details | |
| Mass | 2.44 M☉ |
| Radius | 22.27 R☉ |
| Luminosity | 204.8 L☉ |
| Surface gravity (log g) | 2.50 cgs |
| Temperature | 4,700 K |
| Metallicity | −0.09±0.04 dex |
| Rotational velocity (v sin i) | 3.63 km/s |
| Other designations | |
| e Cyg, 26 Cyg, BD+49°3158, HD 190147, HIP 98571, HR 7660, SAO 49098, ADS 13278, WDS J20014+5006, 2MASS J20012157+5006167 | |
| Database references | |
| SIMBAD | data |
26 Cygni is a single 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. It is located around 451 light-years (138 pc) distant from the Sun, based on parallax measurements. The radial velocity is close to negligible, being measured at −0.3 km/s.
This object is an evolved giant star with a stellar classification of G8 III; 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. It is radiating 205 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,700 K.
There is a magnitude 8.94 visual companion at an angular separation of 41.6″ along a position angle of 150°, as of 2014.
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Fernie, J. D. (1983). "New UBVRI photometry for 900 supergiants". Astrophysical Journal Supplement Series. 52: 7. Bibcode:1983ApJS...52....7F. doi:10.1086/190856.
- ^ Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series. 176 (1): 216–217. Bibcode:2008ApJS..176..216A. doi:10.1086/525529.
- ^ Hekker, S.; Meléndez, J. (2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics. 475 (3): 1003. arXiv:0709.1145. Bibcode:2007A&A...475.1003H. doi:10.1051/0004-6361:20078233. S2CID 10436552.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ 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. arXiv:1805.04094. Bibcode:2018A&A...616A..33S. doi:10.1051/0004-6361/201833111. S2CID 119361866. A33.
- "26 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-11.
- 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22