Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Cygnus |
Right ascension | 21h 42m 05.66458s[1] |
Declination | +51° 11′ 22.6415″[1] |
Apparent magnitude (V) | 4.66[2] |
Characteristics | |
Spectral type | B3 IV[3] |
B−V color index | −0.11[2] |
Astrometry | |
Proper motion (μ) | RA: +5.29[1] mas/yr Dec.: −1.78[1] mas/yr |
Parallax (π) | 1.89 ± 0.15 mas[1] |
Distance | 1,700 ± 100 ly (530 ± 40 pc) |
Absolute magnitude (MV) | −3.91[4] |
Orbit[5] | |
Period (P) | 26.33 d |
Eccentricity (e) | 0.00 |
Periastron epoch (T) | 2431306.5 ± 10.0 JD |
Argument of periastron (ω) (secondary) | 0.00° |
Semi-amplitude (K1) (primary) | 16.5 km/s |
Details | |
π1 Cyg A | |
Mass | 10.1±0.1[3] M☉ |
Radius | 5.6[6] R☉ |
Luminosity | 16,538[7] L☉ |
Temperature | 18,360±1,100[2] K |
Rotational velocity (v sin i) | 55[8] km/s |
Age | 25.1±0.8[3] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Pi1 Cygni (π1 Cygni, abbreviated Pi1 Cyg, π1 Cyg) is a binary star[5] in the northern constellation of Cygnus. It is visible to the naked eye, having a combined apparent visual magnitude of 4.66.[2] The distance to this system can be roughly gauged by its annual parallax shift of 1.89 mas,[1] which yields a separation of around 1,700 light years from the Sun, give or take a hundred light years.
The two components are designated Pi1 Cygni A (officially named Azelfafage /əˈzɛlfəfeɪdʒ/, the traditional name for the system)[10] and B.
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