Sky background level during total lunar eclipse. - David Boyd
I made a rather unusual indirect
observation of the lunar eclipse in the course of observing a variable star in
Lynx about 54 degrees from the eclipsing moon.
As part of the photometry analysis, I extract a measurement of the sky background level around the variable measured in ADU (Analogue to Digital Unit)
counts. The attached plot shows how this varied as the eclipse progressed with the U1, U2 and U3 times marked. The two blips on the downward slope were due to high level cloud, or possibly a plane con trail, passing the star and temporarily raising the background level. Towards the end of totality, the sky
background level started to rise slowly due to thin cloud forming in advance of a weather front. This eventually forced me to abandon photometry before the end of the eclipse.