35 Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 18m 39.06986s |
| Declination | +34° 58′ 57.9909″ |
| Apparent magnitude (V) | 5.18 |
| Characteristics | |
| Spectral type | F6Ib |
| B−V color index | +0.62 |
| Astrometry | |
| Radial velocity (Rv) | −20.20 km/s |
| Proper motion (μ) | RA: −0.05 mas/yr Dec.: −3.77 mas/yr |
| Parallax (π) | 1.03±0.21 mas |
| Distance | approx. 3,200 ly (approx. 1,000 pc) |
| Absolute magnitude (MV) | −3.99 |
| Details | |
| Mass | 10.0 M☉ |
| Radius | 51 R☉ |
| Luminosity | 7,093 L☉ |
| Surface gravity (log g) | 1.5 - 2.4 cgs |
| Temperature | 6,360 K |
| Metallicity [Fe/H] | 0.02 dex |
| Rotational velocity (v sin i) | 3.5 km/s |
| Age | 22 Myr |
| Other designations | |
| 35 Cyg, HR 7770, BD+34°3967, HD 193370, SAO 69806, FK5 3627, HIP 100122 | |
| Database references | |
| SIMBAD | data |
35 Cygni is a spectroscopic binary star in the constellation Cygnus. Its apparent magnitude is 5.18. Located around 1,000 parsecs (3,300 ly) distant, its primary is a yellow supergiant of spectral type F6Ib, a massive star that has used up its core hydrogen and is now fusing heavier elements.
Yellow supergiants are usually variable, often Classical Cepheid variables, but 35 Cyg is notable for having an especially constant brightness.
35 Cyg is a single-lined spectroscopic binary with a period of 2,440 days (over 6 years). The secondary cannot be seen directly, nor can its spectral lines be identified but the overall spectrum can be match by a combination of an F4 supergiant and a less luminous B6.5 star.