NGC2516 Calibration of Secular Changes in EPIC boresight

CAL We observe the SEP region stellar cluster at a number of occasions (5 are included as placeholders) in order to measure the changes in EPICboresight as a function of mission elapsed time, slew leg lengths, posteclipseconditions, solar aspect angle and other variables thought to contribute secularchanges to the EPIC boresight.A modest exposure of 10ks is sufficient to centroid the brightest handful ofXrays sources with high precision. Comparison with ROSAT observations andachival optical data allows to obtain subpixel location accuracy. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]