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LPV at bright end of the light curve and ccd photometry

Ed Wiley_WEY
Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 07/06/2014 - 00:57

Anyone perform B or V photometry on bright LPVs? I had to pass on several mira-class ones last night in the 7-8 v-mag range and was wondering if (1) ccd estimates of stars this bright are welcome and (2) what strategies might be used to deal with scintillation and saturation.

Thanks, Ed 

MZK
Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 07/06/2014 - 02:07
Bright Star CCD Imaging

Of course Ed, that's the whole idea behind the bright star montor (BSM) systems. See description on the aavso web site (search BSM). These are small scopes (60-80 mm). Obviously, you need short images to prevent saturation. With a larger scope, even shorter images are necessary. You could cover part of the scope diameter, but at 7-8 magnitude you just need to shorten the image period to a few seconds. Correct for scintillation by collecting several images and bin/average them in groups of 5 or so. I've even done this with image periods of a few tenths of a second with good precision.

Ken