A test for obscuring clouds in the BLR of the changing look Seyfert 1 H0557-385

We propose to monitor the extreme changinglook Seyfert 1 H0557385. We wantto probe the short time scale variability of the obscuring gas that varied inprevious XMM data. The source was observed in different flux states on a 4 yrtime scale. The flux drop can be entirely explained by lineofsight clouds withNh virgul8*10e23 cm^2 partially covering the nuclear source. This interpretation isvery robust due to the presence of a warm absorber that did not change with thesource flux, possibly suggesting a Broad Line Region origin for the clouds. Thesource has a multicomponent BLR, so we will monitor the optical linesproperties in a proposal for optical spectroscopy and we will request opticalspectra simultaneous to the Xray data. We request 87 ks to be split in 3 XMM observations. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]