56 Cygni
Star in the constellation Cygnus
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56 Cygni is a single[9] star in the northern constellation of Cygnus, located 135[2] light years from Earth. It is visible to the naked eye as a white-hued star with an apparent visual magnitude of 5.06.[3] The star is moving closer to the Earth with a heliocentric radial velocity of −21.5.[3] It has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.181″/yr.[10] According to Eggen (1998), this is a member of the Hyades Supercluster.[11]
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 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 20h 50m 04.93165s[2] |
| Declination | +44° 03′ 33.4916″[2] |
| Apparent magnitude (V) | 5.06[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | A6 V[4] |
| B−V color index | 0.198±0.002[1] |
| Astrometry | |
| Radial velocity (Rv) | −21.5±3.5[3] km/s |
| Proper motion (μ) | RA: +123.197[2] mas/yr Dec.: +132.062[2] mas/yr |
| Parallax (π) | 24.2284±0.0747 mas[2] |
| Distance | 134.6 ± 0.4 ly (41.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.00[1] |
| Details | |
| Mass | 1.89[5] M☉ |
| Radius | 1.92[5] R☉ |
| Luminosity | 12.8[5] L☉ |
| Surface gravity (log g) | 4.15±0.07[5] cgs |
| Temperature | 7,895±127[5] K |
| Rotational velocity (v sin i) | 73[6] km/s |
| Age | 394[7] Myr |
| Other designations | |
| 56 Cyg, BD+43°3739, FK5 3666, HD 198639, HIP 102843, HR 7984, SAO 50121, WDS J20501+4404[8] | |
| Database references | |
| SIMBAD | data |
This is an A-type main-sequence star with a stellar classification of A6 V.[4] Cowley et al. (1969) classified it as a Delta Delphini star,[12] which is a type of suspected Am star. The star is around 394[7] million years old with a projected rotational velocity of 73 km/s.[6] It has 1.9 times the mass of the Sun and is radiating 13 times the Sun's luminosity from its photosphere at an effective temperature of 7,895 K.[5]
56 Cygni has a visual companion: a magnitude 11.9 star at an angular separation of 55.4″ along a position angle of 48°, as of 2015.[13]