Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 08/17/2014 - 15:31
I just downloaded a bunch of images from OC61 taken from late July through Aug. 11. There are several prominent dust donuts and other defects visible on all of these images. Were bad flats used? Will these images be reprocessed with better flats and, if so, when? I'd like to measure these images soon and submit the observations but I don't want to do this twice.
Bob
Hi Bob,
You get images from ~140731 through ~140811 in quick succession, because the "automatic" file transfer script had not reset itself properly after a computer reboot.
I don't see anything obvious with the images, other than the fact that the flats were a bit stale (B,SI from 140725, for example). However, remember that this period is near full moon (which was August 8), and this is an open-truss telescope. As such, you will see more scattered light/dust donuts in your images when the moon is up.
Bottom line is that I think things were running ok, and you can submit your photometry. I will ask Mt. John to pull the camera and clean it before the next full moon, to alleviate some of the dust issues.
Arne