Looking for a thermal emission component in BL Lacertae

We propose to observe BL Lacertae with XMMNewton three times in AO6, toconstruct its SED in different brightness states. Our interest is focused on theUV and soft Xray energy domains, and this makes XMMNewton the ideal instrumentto attain our goal, which is to investigate the existence of a UV to softXraybump, as we detected in AO 0235+16 with observations in AO3. This would meanthat in BL Lac objects there may be an important emission component in additionto the synchrotron and inverseCompton ones, which is likely the photoionizingsource of the broad line region, similarly to the blue bump of FSRQs.Simultaneous observations at low frequencies by the WEBT will allow to to studythe correlations among the emissions at different wavelengths. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]