Table 7: Two different effects are responsible for the destruction of circumstellar disks around O stars; the photo-evaporation process and the direct interaction between the wind and the disk. In the first 3 columns, the stellar parameters are given used in the calculation of the timescales (Mokiem et al. 2004; Lenorzer et al. 2004). In Col. 4, the gravitational radius is given. Beyond this radius matter is removed by photoevaporation, while inside of it, the stellar wind directly removes material from the disk. Cols. 5 and 6 give the typical timescales for these two processes. The formulae are taken from Hollenbach et al. (2000,1994).
SpTp log ( $Q{_{\rm0}}$) log ( \ensuremath{\dot{M}}) $r_{\rm g}$ $t_{\rm p}$ $t_{\rm w}$
  s-1 $M_{\odot}$ yr-1 AU 105 yr 105 yr

O3V		 49.69 -5.375 459.5 0.6 0.7
O4V 49.50 -5.599 377.4 0.8 1.1
O5V 49.31 -5.805 301.4 0.9 1.8
O5.5V 49.08 -6.072 251.4 1.1 3.3
O6.5V 48.82 -6.369 205.4 1.3 6.5
O7.5V 48.51 -6.674 169.4 1.7 13.3
O9V 48.06 -7.038 141.4 2.5 30.7
O9.5V 47.79 -7.252 128.7 3.3 50.1
O9.7V 47.52 -7.445 118.0 4.2 78.8
B1V 46.92 -7.913 98.7 7.3 233.5


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