26 Cygni
Giant star in the constellation Cygnus
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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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 01m 21.56485s[1] |
| Declination | +50° 06′ 16.8912″[1] |
| Apparent magnitude (V) | 5.12[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | G8 III[4] |
| B−V color index | 1.122[5] |
| 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 mas[1] |
| Distance | 451 ± 5 ly (138 ± 2 pc) |
| Absolute magnitude (MV) | −0.56[6] |
| Details | |
| Mass | 2.44[3] M☉ |
| Radius | 22.27[3] R☉ |
| Luminosity | 204.8[3] L☉ |
| Surface gravity (log g) | 2.50[5] cgs |
| Temperature | 4,700[5] K |
| Metallicity [Fe/H] | −0.09±0.04[6] dex |
| Rotational velocity (v sin i) | 3.63[5] 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[7] | |
| Database references | |
| SIMBAD | data |
This object is an evolved giant star with a stellar classification of G8 III;[4] 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.[3] It is radiating 205 times the luminosity of the Sun from its enlarged photosphere[3] at an effective temperature of 4,700 K.[5]
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]