Radio Evidence on the Mass Loss Bistability Jump

Benaglia, P.; Vink, J. S.; Martí, J.; Maíz-Apellániz, J.; Koribalski, B.; Johnston, S.
Mass Loss from Stars and the Evolution of Stellar Clusters ASP Conference Series, Vol. 388, proceedings of the conference held 29 May - 1 June 2006, in Lunteren, The Netherlands. Edited by Alex de Koter, Linda J. Smith, and Laurens B. F. M. Waters. San Francisco: Astronomical Society of the Pacific, 2008., p.141


We present the results of a first campaign of radio continuum observations toward supergiants with spectral types in the range O8 - B3. Three targets out of twelve were detected with the ATCA and the VLA. The measured fluxes and the upper limits yielded values of the stellar mass-loss rates dot{M} and the wind efficiencies. The comparison of predicted and derived values of dot{M} shows a good agreement.