63 Cygni
K-type bright giant/supergiant star in the constellation Cygnus
From Wikipedia, the free encyclopedia
63 Cygni is a single[9] star in the northern constellation of Cygnus, located around 1,030 light years away from Sun. It is visible to the naked eye as an orange-hued star with an apparent visual magnitude of 4.56.[2] 63 Cyg is moving closer to the Earth with a heliocentric radial velocity of −26 km/s.[2]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 06m 36.103s[1] |
| Declination | +47° 38′ 54.22″[1] |
| Apparent magnitude (V) | 4.56[2] |
| Characteristics | |
| Spectral type | K4 Ib–IIa[3] |
| B−V color index | 1.569±0.012[2] |
| Astrometry | |
| Radial velocity (Rv) | −26.32±0.23[2] km/s |
| Proper motion (μ) | RA: +5.992[4] mas/yr Dec.: −1.067[4] mas/yr |
| Parallax (π) | 2.66±0.29 mas[4] |
| Distance | approx. 1,200 ly (approx. 380 pc) |
| Absolute magnitude (MV) | −2.93[5] |
| Details | |
| Radius | 138[1] R☉ |
| Luminosity | 3,981 - 4,130[1] L☉ |
| Surface gravity (log g) | 1.27[6] cgs |
| Temperature | 3,927[1] K |
| Metallicity [Fe/H] | 0.12[6] dex |
| Rotational velocity (v sin i) | 6.3[7] km/s |
| Other designations | |
| f2 Cyg, 63 Cyg, BD+47°3292, FK5 3688, HD 201251, HIP 104194, HR 8089, SAO 50456, WDS J21066+4739[8] | |
| Database references | |
| SIMBAD | data |
This is an evolved star showing a stellar spectrum with mixed traits between a bright giant and supergiant. It has been chosen as a spectral standard for the class of K4 Ib–IIa.[3]
For reasons that are not yet clear, 63 Cygni is displaying very long period (982 days) and low-amplitude (742 m/s) variations in radial velocity.[2] The star has expanded to 35[2] times the Sun's radius and is radiating 4,397[5] times the Sun's luminosity from its photosphere at an effective temperature of 4,204 K.[6]