Several photometrists are finding errors in observation times from a software bug and corrections are going to be issued by them. I use Richard Berry's Photomet v.27 for reductions. I checked it against the calculated JD in my Excel spreadsheet SunTime.xls (which calculates JD in addition to heliocentric corrections). The times reported by Photomet are correct within the clock accuracy of the computer to the mid point of the exposures. I make checks of the clock every couple of hours with NIST, as errors of several seconds in the computer clock may accumulate throughout the night. I divide the data up so that the clock error is less than 3 seconds for my reported data. Heliocentric corrections are usually not made in data reported out to VS-Net, CBA archive or AAVSO. If anyone wants to use the spreadsheet it is available free from the descriptive page http://vsnet.geocities.com/lcoo/SUNTime.htm ===== Regards, Lew http://vsnet.geocities.com/lcoo/ __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com