Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus |
Right ascension | 20h 53m 14.75503s[1] |
Declination | +44° 23′ 14.1408″[1] |
Apparent magnitude (V) | 4.80[2] |
Characteristics | |
Spectral type | B5 V[3] |
B−V color index | −0.134±0.006[2] |
Astrometry | |
Radial velocity (Rv) | −21.1±2.8[2] km/s |
Proper motion (μ) | RA: +11.94[1] mas/yr Dec.: −2.08[1] mas/yr |
Parallax (π) | 6.21 ± 0.22 mas[1] |
Distance | 530 ± 20 ly (161 ± 6 pc) |
Absolute magnitude (MV) | −1.23[2] |
Orbit[4] | |
Period (P) | 2.8548 days |
Eccentricity (e) | 0.139±0.014[5] |
Inclination (i) | ≈ 48[6]° |
Periastron epoch (T) | 2441571.275 JD |
Argument of periastron (ω) (secondary) | 159.6° |
Semi-amplitude (K1) (primary) | 111.9 km/s |
Semi-amplitude (K2) (secondary) | 126.0 km/s |
Details | |
57 Cyg A | |
Mass | 5.54±0.55[5] M☉ |
Radius | 3.3±0.4[4] R☉ |
Temperature | 17,190[7] K |
Rotational velocity (v sin i) | 40[8] km/s |
57 Cyg B | |
Mass | 4.92±0.49[5] M☉ |
Radius | 2.9±0.4[4] R☉ |
Rotational velocity (v sin i) | 30[8] km/s |
Other designations | |
Database references | |
SIMBAD | data |
57 Cygni is a close binary star[4] system in the constellation Cygnus, located about 530 light years from Earth. It is visible to the naked eye as a blue-white hued star with a baseline apparent visual magnitude of 4.80.[2] The pair have a magnitude difference of 0.34.[4] This system is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[2]
This is a double-lined spectroscopic binary with an orbital period of 2.85 days and an eccentricity of 0.15.[4] They show a steady change in their longitude of periastron, showing an apsidal period of 203±4 years.[10] The system does not form an eclipsing binary, having the orbital inclination of around 48°.[6] Both components are B-type main-sequence stars with a stellar classification of B5 V.[4]
vanLeeuwen2007
was invoked but never defined (see the help page).Anderson2012
was invoked but never defined (see the help page).Lesh1968
was invoked but never defined (see the help page).Hilditch1973
was invoked but never defined (see the help page).DeLaurentis2012
was invoked but never defined (see the help page).Jetsu1999
was invoked but never defined (see the help page).Zorec2009
was invoked but never defined (see the help page).Abt2002
was invoked but never defined (see the help page).SIMBAD
was invoked but never defined (see the help page).Tapia1979
was invoked but never defined (see the help page).