Monday, December 27, 2010

A 24" and an 8"

I went out last night to our club's observatory, and got to learn a bit of my way around controlling the observatory's 24" Ritchey-Chretien.  My plan was to look at clusters in M31.  I did all the observing in the 24" through the camera, with exposures from 5 to 200 seconds.  I started with a very quick and shapely image of the spiral galaxy M74 that I didn't save.  And M76, the Little Dumbbell, looked like its big cousin.  I tried for a galaxy cluster, but at my exposure times I could barely see anything.

Then I moved on to what I was primarily aiming at: the M31 clusters.  I did see G1, G76, G78, G81 and G280.  The hard part wasn't seeing the objects, but identifying them, as at the resolution of the camera I was using they all just looked like stars, as can be seen in my photo on the right, except maybe G1 (the bigger circles are just brighter stars).  G1 has two stars from our galaxy really close to it and looks like the head of Mickey Mouse, with the stars being its ears, which made it easy to identify.  The others I just had to correlate against SIMBAD images and the M31 clusters catalog in AstroInfo.  Since AstroInfo only goes up to magnitude 12.7 in stars, there were very few stars in each camera field of view to correlate with, but I think I did manage to identify all the objects by their relative positions to these stars.

I also looked at one open cluster in M31 for good measure: VDB0-B195D.  It looked like it had some detail around the bottom edge, though the supposed detail may just be foreground Milky Way stars.  The photo also captured NGC 206, a fragment of M31, and a bunch of prominent dark lanes in the M31 background.  None of these are amazing photos--they're more like quick observing.

I ended up my session on the 24" with a look at Comet Hartley, which I hadn't seen since earlier in the fall.  It was fairly low in the sky, but it was definitely there (see glow to left of center).  I was pleased that 2sky got its position correct.

I then went to the observing field to pick up my Coulter 8" which I had put out in the field at the beginning of the night.  There was ice on the tube, but the scope worked great (except for a problem with the red dot finder that I need to fix).  I had a quick look at M33.  I couldn't see the spiral arms, but I did see hints of detail, and it was quite large.  And then I looked at M42 and it had lovely color: greenish-blue near the Trapezium, moving to reddish-pink in the wings.

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