Ad Astra Observatory

<http://www.skyandtelescope.com/observing/highlights/10775326.html>

Hi all,

Comet 17P/Holmes is a very obvious “new star” in Perseus, about 3 or 4

degrees southeast of Algol in Perseus. With 10×50 binoculars, it was
definitely (!) non-stellar. In the 2000mm SCT at 62.5x, the bright core was
visible, with a nearly-concentric-circle bullseye looking pattern around it.

I didn’t have the SCT ready to go for photography, so I set up Pumpkin
(400mm refractor) instead. After a quick focus on the moon and a few test
shots to make sure I wasn’t overexposing the image, here’s what I came up

with. I was shooting through the clouds, and it’s cloudy this morning.
Maybe it’ll clear up again for tonight so I can take another shot at it.

If you have anything like a clear view to the northeast, get out there
tonight and take a look!

Keep looking up,
Jimbo

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Hi all,

I decided to get Kate the SCT focused so that I could get a more “zoomed
in” shot of the comet. The skies cooperated just enough to let me get it done.

I’ve attached the result.

Interesting things to note: even though Kate is 8” (200mm) and Pumpkin is

only 2.5” (66mm), because Kate’s focal ratio is so much greater (f/10
versus f/6), the image shows much less outer halo detail (the “green ring”
around the comet in the first photo). All that light is spread out over
more area, so it’s a dimmer image (although much, much larger).

I was having trouble with tracking tonight; the stars are definitely not
round. However, as I was processing the image, I noticed that the comet

jumped around relative to the background stars, too (the processing sorts
images by “quality”, so the jumping was likely a steady progression, if
watched in chronological order). I shot 50 frames, 30 seconds each, delay
of 5 seconds in between, so it took basically 30 minutes between the first
shot and the last. Apparently these things move.

Enjoy.

Clear skies,

Jimbo

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