Observation of H2 regions around ζOph and other O-B stars

Using the Fabry-Perot spectrometer the emission intensities in Hβ near ξOph, αCam, αOri and HD 188209 stars are measured. The spectrometer sensibility is 0.2 Reyleighs (emission measure ∼ 2 pk/cm6), the accuracy of intensity measurement is 20%. The boundaries of ionization zones are determined for ξOph and αVir. The angle diameter of both regions are about 15 deg. The contour of H2 region near ξOph on the level of double background in South-West does not close but expands again including the region connected with B-association IISco. The average ne in H2 region and U(Sp) of the stars are determined. Taking into account the adopted distances of the agreement of observatory ionization zones diameters with the Lyman-continuum photon flux from stars is received for spectral types 09V (ξOph) and BO.7IV(αVir). For the other stars the theoretical diameters of ionization zones are determined