SAS watchout

EPIC light curves using evselect or epiclccorr?

SAS users should be warned that evselect is able to extract light curves but not to correct them. Especially binning evselect-extracted light curves close to the frame time limit may produce strange results, partly attributable to simple aliasing effects, partly under investigation, since it has been reported that this cannot be the full explanation. Therefore, while evselect can be used for obtaining qualitative light curves, proper corrected light curves as for science analysis should be obtained using the SAS task epiclccorr.