HD 168625
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 21m 19.54840s |
| Declination | −16° 22′ 16.0751″ |
| Apparent magnitude (V) | 8.30–8.41 |
| Characteristics | |
| Spectral type | B6Ia+ (B2—B8) May be B60 due to hypergiant designation |
| U−B color index | +0.37 |
| B−V color index | +1.41 |
| J−K color index | 0.599 |
| Variable type | α Cygni |
| Astrometry | |
| Radial velocity (Rv) | −4.00 km/s |
| Proper motion (μ) | RA: +0.304 mas/yr Dec.: −1.978 mas/yr |
| Parallax (π) | 0.6542±0.0259 mas |
| Distance | 5,000 ± 200 ly (1,530 ± 60 pc) |
| Absolute magnitude (MV) | −8.39 |
| Details | |
| Radius | 105 R☉ |
| Luminosity | 380,000 L☉ |
| Surface gravity (log g) | 1.74 cgs |
| Temperature | 14,000 K |
| Rotational velocity (v sin i) | 60 km/s |
| Other designations | |
| V4030 Sgr, HD 168625, BD−16°4830, SAO 161375, HIP 89963, AAVSO 1815-168 | |
| Database references | |
| SIMBAD | data |
HD 168625 (V4030 Sagittarii) is a blue hypergiant star and candidate luminous blue variable located in the constellation of Sagittarius easy to see with amateur telescopes. It forms a visual pair with the also blue hypergiant (and luminous blue variable) HD 168607 and is located to the south-east of M17, the Omega Nebula.