Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Sagittarius |
Right ascension | 18h 07m 11.35s[1] |
Declination | −21° 26′ 38.2″[1] |
Apparent magnitude (V) | +6.33[2] |
Characteristics | |
Spectral type | B1/2Ib[3] |
U−B color index | −0.72[2] |
B−V color index | +0.12[2] |
Astrometry | |
Radial velocity (Rv) | -8.50[4] km/s |
Proper motion (μ) | RA: −0.23[1] mas/yr Dec.: −1.15[1] mas/yr |
Parallax (π) | 1.39 ± 0.49 mas[1] |
Distance | approx. 2,300 ly (approx. 700 pc) |
Absolute magnitude (MV) | −5.8[5] |
Details | |
Mass | 10.1[6] M☉ |
Radius | 26[7] R☉ |
Temperature | 25,000[8] K |
Rotational velocity (v sin i) | 55[9] km/s |
Age | 22.5[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 165516 is a blue supergiant star in the constellation Sagittarius. It is part of the Sagittarius OB1 association and appears against a rich Milky Way starfield near the Triffid Nebula and Lagoon Nebula.
HD 165516 is close to a small reflection and emission nebula, and an associated loose open cluster. The nebula is catalogued as GN 18.05.6,[10] but was first listed as VdB 113.[11] That name has since been used for the cluster itself, which is likely more distant than HD 165516. The whole cluster is less than a quarter of a degree across, with dozens of members from 8th magnitude downwards. V4381 Sagittarii is listed as a probable member, while HD 165516 and the nearby Wolf-Rayet star WR 111 are considered unlikely to be members.[12]