The measurement of masses of OB-type stars from LAMOST DR5

The measurements of masses and luminosities of massive stars play an important role in understanding the formation and evolution of their host galaxies. In this work, we present the measurement of masses and luminosities of 2,946 OB-type stars, including 78 O-type stars and 2,868 B-type stars, based on their stellar parameters (effective temperature, surface gravity, and metallicity) and PARSEC isochrones model. Our results show that the median mass and luminosity of the 2,946 OB-type stars are 5.4 M$_{\odot}$ and log(L/L$_{\odot}$)=3.2 with the median relative error of 21.4$\%$ and 71.1$\%$, respectively. A good agreement between our results estimated by using our method and those derived by using the orbital motions of binary stars from the literature is found for some B-type stars. In addition, we also fit the mass-luminosity relation of B-type stars by using our derived mass and the luminosity from $Gaia$ DR3.