Pi1 Cygni
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) |
|
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 42m 05.66458s |
| Declination | +51° 11′ 22.6415″ |
| Apparent magnitude (V) | 4.66 |
| Characteristics | |
| Spectral type | B3 IV |
| B−V color index | −0.11 |
| Astrometry | |
| Proper motion (μ) |
RA: +5.29 mas/yr Dec.: −1.78 mas/yr |
| Parallax (π) | 1.89 ± 0.15mas |
| Distance | 1,700 ± 100 ly (530 ± 40 pc) |
| Orbit | |
| 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 M☉ |
| Radius | 5.6 R☉ |
| Luminosity | 16,538 L☉ |
| Temperature | 18,360±1,100 K |
| Rotational velocity (v sin i) | 55 km/s |
| Age | 25.1±0.8 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Pi1 Cygni (π1 Cygni, abbreviated Pi1 Cygni, π1 Cygni), also named Azelfafage, is a binary star system in the northern constellation of Cygnus. It is visible to the naked eye, having a combined apparent visual magnitude of 4.66. The distance to this system can be roughly gauged by its annual parallax shift of 1.89 mas, which yields a separation of around 1,700 light years from the Sun, give or take a hundred light years.
This is a single-lined spectroscopic binary with a close, circular orbit, having a period of just 26.33 days. The primary, component A, is a slightly evolved B-type subgiant star with a stellar classification of B3 IV. It has an estimated 10 times the mass of the Sun and around 5.6 times the Sun's radius. The star radiates 16,538 times the solar luminosity from its outer atmosphere at an effective temperature of roughly 18,360 K. It is about 25 million years old and is spinning with a projected rotational velocity of 55 km/s.
π1 Cygni (Latinised to Pi1 Cygni) is the star's Bayer designation. It is also designated HIP 107136 and HR 8301
...
Wikipedia