Omicron Herculis

o Herculis
Location of o Herculis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 18h 07m 32.55073s
Declination +28° 45 44.9679
Apparent magnitude (V) 3.83
Characteristics
Spectral type B9.5III
U−B color index −0.07
B−V color index −0.02
Variable type γ Cas
Astrometry
Radial velocity (Rv)−29.5 km/s
Proper motion (μ) RA: −0.02 mas/yr
Dec.: +8.55 mas/yr
Parallax (π)9.65±0.16 mas
Distance338 ± 6 ly
(104 ± 2 pc)
Absolute magnitude (MV)−1.24
Details
Mass3.49±0.04 M
Radius6.3 R
Luminosity355 L
Surface gravity (log g)2.86 cgs
Temperature9,484 K
Metallicity [Fe/H]−0.06 dex
Rotational velocity (v sin i)194 km/s
Other designations
o Her, 103 Herculis, BD+28 2925, FK5 681, HD 166014, HIP 88794, HR 6779, SAO 85750
Database references
SIMBADdata

Omicron Herculis, Latinized from o Herculis, is a star in the constellation Hercules. It used to be called Masym ("the wrist"), but this name was transferred to Lambda Herculis.