Ad Astra Observatory

fullsize image

I finally decided to try out Veronica (the 8” f/5 Newtonian) in the observatory, instead of the ED80.

The reflector has two distinct advantages over the ED80; first, it’s about 2 f/stops faster (f/5 vs f/7.5), so it sucks up light 4 times as fast (each f/stop has a 2x effect on exposure length) second, its longer focal length (1000mm vs 600mm) will allow me to “zoom in” a little and hopefully allow me to pick up some smaller targets.

However, Veronica weighs over 11lb more than the ED80, and I was worried how the mount would handle the extra load.

I guess having a 6” steel pier and 4′ of concrete under the mount stiffens things up a bit; the AS-GT worked just fine.

This image was shot unguided; the mount hung in there for each 30sec exposure without skipping a beat.

Oh, I noticed one more advantage to the reflector while I was shooting: The mirror doesn’t pass as much IR
as the refractor’s lenses do, so the red channel didn’t blow out as fast, despite all the extra light-gathering.

Not bad.
Oh, last thing. This was on a night with a 16-day (that is, almost-full) moon. Whoa.