Energy distributions of the slew survey-detected sources of the AGB star W Cyg and WD HZ 43. Single events (pattern number 0, solid lines) are the most reliable events in an XMM X-ray source, while double events (pattern numbers 1−4, dashed lines) are events with charge spread over two pixels. The distribution of single and double events in HZ 43 is the expected distribution for a soft and bright X-ray source, whereas the distributions exhibited by W Cyg and the other AGB stars detected in the slew survey (L₂ Pup, R Dor, and R Leo), are indicative of optical loading from these bright red stars.