V1331 Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 01m 09.20684s |
| Declination | +50° 21′ 44.8033″ |
| Apparent magnitude (V) | 11.99 |
| Characteristics | |
| Spectral type | G7-K0IV |
| Astrometry | |
| Proper motion (μ) | RA: 0.980 mas/yr Dec.: −3.783 mas/yr |
| Parallax (π) | 1.6760±0.0237 mas |
| Distance | 1,950 ± 30 ly (597 ± 8 pc) |
| Details | |
| Mass | 2.8 M☉ |
| Radius | 5 R☉ |
| Temperature | 5200 K |
| Other designations | |
| V1331 Cyg, GSC 03596-00959, 2MASS J21010920+5021445 | |
| Database references | |
| SIMBAD | data |
V1331 Cygni (also known as V1331 Cyg) is a young star in the constellation Cygnus. V1331 Cyg is located in the dark nebula LDN 981.
V1331 Cygni is most noted for having an arc-like reflection nebula surrounding it. This circumstellar disc is a great birthplace for young stars, which form in the cloud. V1331 Cygni is heavily obscured by dust, so the properties of the central star are hard to deduce; however, it is estimated to have a radius five times that of the Sun and a mass of 2.8 M☉.
The General Catalog of Variable Stars classifies V1331 Cygni as an "INST" type variable, meaning a T Tauri star which shows rapid light variations. Its visual band brightness varies from magnitude 13.08 to 10.58. It is sometimes classified as a pre-FUOR star. A semi-regular period of ~449 days has been reported. Unlike many T Tauri stars, the mean brightness of V1331 Cygni remains nearly constant over long time periods.