| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h50m 04.93129s[1] |
| Declination | +44° 03′ 33.4862″[1] |
| Apparent magnitude (V) | 5.06[2] |
| Characteristics | |
| Spectral type | A6 V[3] |
| B−V color index | 0.198±0.002[4] |
| Astrometry | |
| Radial velocity (Rv) | −21.5±3.5[2] km/s |
| Proper motion (μ) | RA: +123.450[1] mas/yr Dec.: +132.420[1] mas/yr |
| Parallax (π) | 24.1034 ± 0.1344 mas[1] |
| Distance | 135.3 ± 0.8 ly (41.5 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.00[4] |
| Details[5] | |
| Mass | 1.72 M☉ |
| Luminosity | 13.19[4] L☉ |
| Surface gravity (log g) | 4.28±0.14 cgs |
| Temperature | 8,124±276 K |
| Rotational velocity (v sin i) | 73[6] km/s |
| Age | 394 Myr |
| Other designations | |
56 Cyg, BD+43°3739, FK5 3666, HD 198639, HIP 102843, HR 7984, SAO 50121, WDS J20501+4404[7] | |
| Database references | |
| SIMBAD | data |
56 Cygni is a single[8] star in the northern constellationofCygnus, located 135[1] light years from Earth. It is visible to the naked eye as a white-hued star with an apparent visual magnitude of 5.06.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −21.5.[2] It has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.181″/yr.[9] According to Eggen (1998), this is a member of the Hyades Supercluster.[10]
This is an A-type main-sequence star with a stellar classification of A6 V.[3] Cowley et al. (1969) classified it as a Delta Delphini star,[11] which is a type of suspected Am star. The star is around 394[5] million years old with a projected rotational velocity of 73 km/s.[6] It has 1.72[5] times the mass of the Sun and is radiating 13[4] times the Sun's luminosity from its photosphere at an effective temperature of 8,124 K.[5]
56 Cygni has a visual companion: a magnitude 11.9 star at an angular separationof55.4″ along a position angle of 48°, as of 2015.[12]
