Parameters of OB stars & their bow shock nebulae

Motivated by the need to reconcile observational values and theory, we use a recently vetted technique to analyze the mass-loss rates in a sample of OB stars that generate bow shock nebulae. We measure peculiar velocities from new Gaia parallax and proper motion data and their spectral types from new optical and infrared spectroscopy.

For our sample of 70 central stars in morphologically selected bow shock nebulae, 67 are OB stars. The median peculiar velocity is 11 km/s, significantly smaller than classical "runaway star" velocities. Mass-loss rates for these O and early B stars agree with recently lowered theoretical predictions, ranging from ~10^-7^ M_{sun}_/yr for mid-O dwarfs to 10^-9^ M_{sun}_/yr for late O dwarfs - a factor of about 2.7 lower than the often-used Vink et al. (2000A&A...362..295V, 2001A&A...369..574V) formulation.