Guiding foiled by Arachnid

While imaging something occurred I thought is worth sharing. My equipment consists of APMach1 GTO mount, Televue 101is refractor and Orion 50 mm guide scope. Besides SGP I use PhD2 Guiding and Astro-Physics APCC.
Part way through a 15 minute sub a dialog box appears in SGP that states Event Alert. I look at the PhD2 guiding graph and the line which was looking nice and flat shows a massive spike, something akin to a heartbeat in an EKG tracing. I have never seen this before and have no idea what caused the Alert or what to do about it. The sub was aborted. The guiding graph went flat and I resumed imaging. The same thing happened two more times so I deceided to shut everything down. While placing the cap over the guide scope my red headlamp picked up a spider crawling down the side of the guide scope. Relief swept over me as I discovered the reason for the Event Alerts. Next night I sprayed the Astrozap dew heater guide scope band with DEET. and imaged without any Alerts. Who could have anticpated such a thing?
Wishing you clear skies free of spiders!


My observatory was a haven for creepy crawlies until I sprayed it. I use a handheld spray bottle filled with water, a few drops of washing up liquid, a few drops of peppermint oil and also of lavender oil.

I wouldn’t want to breath in DEET - but I have one sweet-smelly obsy and no spiders!

I treat all the crevices once a month.


Thanks for that information!!!

Indeed, I hang a no pest strip in my roll-off. Even then, the floor is covered with flies. I heard a tale of a giant blob in an image and horrible guiding. It was an owl perched on the dew shield. Maybe just a tale, but cool anyway. Those guys are huge - at least the great horned we have around here…