[Eric Hahl]

The cooler gets the temp down about -50F from ambient. So, if its 80f outside the sensor can get down to 30f.
I was doing some long exposures (10 and 15 minutes) and it definitely shows amp glow from the sensor on the top of the picture. For this particular shot, the hydrogen and oxygen were shot on the east side of the meridian and the sulfur was shot on the west side so I got the glow both top and bottom.

I'm going to try shorter exposures with a break in between shots to cool the chip down each exposure and see what happens.

Thanks for the advice!