HD 179821
 HD 179821 Credit: Hubble Legacy Archive | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 13m 58.61s |
| Declination | +00° 07′ 31.9″ |
| Apparent magnitude (V) | 8.19 |
| Characteristics | |
| Evolutionary stage | YHG or post-AGB |
| Spectral type | G4 0-Ia |
| Variable type | SRd |
| Astrometry | |
| Distance | 17,000 ly |
| Absolute magnitude (MV) | −8.9 |
| Details | |
| Mass | 17 - 22 M☉ |
| Radius | 400 - 450 R☉ |
| Luminosity | 126,000 - 295,000 L☉ |
| Temperature | 4,898-6,761 K |
| Other designations | |
HD 179821 or V1427 Aquilae is a post-red supergiant yellow hypergiant star in the constellation of Aquila. It is surrounded by a detached dust shell. It is a semi-regular variable nearing the end of its life.