HD 108
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h 06m 03.389s |
| Declination | +63° 40′ 46.77″ |
| Apparent magnitude (V) | 7.40 |
| Characteristics | |
| Spectral type | O4–8f?p |
| U−B color index | −0.61 |
| B−V color index | 0.18 |
| Astrometry | |
| Radial velocity (Rv) | −63.3±0.3 km/s |
| Proper motion (μ) | RA: −4.284 mas/yr Dec.: −1.992 mas/yr |
| Parallax (π) | 0.4980±0.0240 mas |
| Distance | 6,230 ± 360 ly (1,910±110 pc) |
| Details | |
| Mass | 42±5 M☉ |
| Radius | 19.4±1.5 R☉ |
| Luminosity | 5.0+1.3 −1.0×105 L☉ |
| Surface gravity (log g) | 3.50±0.10 cgs |
| Temperature | 35,000±2,000 K |
| Rotation | 55 years |
| Age | 3.3±0.3 Myr |
| Other designations | |
| NSV 25, AAVSO 0000+63, BD+62°2363, GC 85, HD 108, HIP 505, SAO 10973, WDS J00061+6341AB | |
| Database references | |
| SIMBAD | data |
HD 108 is a massive, peculiar star in the northern circumpolar constellation of Cassiopeia. At an apparent visual magnitude of 7.40, it is too faint to be visible to the naked eye. HD 108 is located at an estimated distance of 6,230 ± 360 light-years (1.91 ± 0.11 kpc) from the Sun, but is drifting closer with a line of sight velocity of −63 km/s. Based on its proper motion, it is a likely member of the Cas OB5 association of co-moving stars.
This is a massive O-type star with a stellar classification of O4–8f?p. It has around 42 times the mass of the Sun and 19 times the Sun's radius. The star is radiating 500,000 times the luminosity of the Sun from its photosphere at an effective temperature of 35,000 K. In 2023, long-term monitoring of radial velocity suggested an orbiting companion with a period of 8.5 years and a mass of at least 4 M☉.