[PRejto (Peter)]

Hi Ernie and Paul,

Well, you guys could be right of course. But, it was a really good night. I was using PEMpro, not TSX, and imaging at .96 arc-sec, .5 sec exposures with the SX Trius camera. During capture of the 5 cycles I could tell it was a good run because as the exposures are plotted on the graph in PEMpro it's quite easy to see how much the atmosphere is affecting things. In poor seeing the points jump all over the place and then on the next cycle they are jumping too but not in the same direction necessarily. Last night there was very little jumping around and the trends over the 5 cycles were quite consistant. And then after applying the correction the result was even flatter. It's kind of hard for me to figure out how that is noise. I'm not saying you guys are wrong but just trying to understand. If the first run was wrong and it was noise how could that then result in an improvement? Or, another question? How can "noise" make it appear that there is no PE? Wouldn't noise make stars jump all over the place?

Anyway, here is a look at the PE capture in PEMpro with PEC off that resulted in the correction curve posted earlier. I've also attached the PEMpro txt file.

Please tell me if you see something wrong! Each cycle of the worm is a different colour. The variations within each cycle can be read in pixels on the left. The reason the cycles don't exactly line up is due to drift in RA due to polar alignment. So over 5 cycles (12.5 min) I've drifted 4-5 arc-sec.

Paul, with PEMpro you cannot select the star as it is done automatically and the exposure adjusted accordingly. Also, I'm not sure I understand what you mean exactly by "East Coast." Sure, the seeing might be poor and normally exceed 2 arc-sec, but that would be the noise. The measured PE would be hidden in the noise, but it would (or should) be the same no matter where the mount was located.

Peter