090041

The hot corona is central for our understanding of the X-ray emission of activegalactic nuclei (AGN). Beside its importance in fact we have very littleknowledge about the corona. The last years established a new viewing angle as afew observations allowed to observe the building of a hot corona especially inthe context of tidal disruption events. Unfortunately this observations had tofollow an opportunistic approach which substantially limits their significance.Here we propose a systematic monitoring of the building of a corona in ESO253-G003. ESO 253-G003 shows a strongly periodic disruption of its X-rayemission every virgul114 days and subsequent recovery of its X-ray emitting hotcorona within 20 days. This offers a unique opportunity to systematically monitor the raise of a corona. [truncated! Please see actual data for full text]