Las Cienegas
(Empire Ranch, near Sonoita, AZ)

November 22 - 23, 2006

25" f/5 Obsession

I wasn't planning on observing over the Thanksgiving holiday because the TAAA star party was the previous Saturday and I figured I missed that opportunity for a new Moon viewing session. My plans changed, however, after reading a message on the AZ-Observing list serve from Renato Del Rosario. Renato is from Benicia, CA and was visiting SE Arizona over Thanksgiving and had wondered if anyone would like to go out viewing. I figured this was a good chance to do some new Moon viewing while we were enjoying some warmer than usual Fall temperatures in the area. Andrew Cooper also responded that he was interested so we made plans to caravan out to Las Cienegas on late Wednesday afternoon. Renato brought his 12.4" Portaball and Andrew showed up with his homemade 18", which he affectionately calls "Deep Violet". We got to the observing site around 5:30 PM and were treated to a very nice sunset with a thin crescent Moon. Andrew and I both had Canon 20Da's and snapped some shots while Renato was setting up.

The ServoCat drive on the 25" wasn't working most likely because of a bad encoder on the Alt motor. I will be taking the scope to Gary Myers to have him get this fixed. Fortunately, the encoders used by the Argo Navis worked just fine. Actually, the Argo Navis worked very well all night long because I never had to do a re-alignment beyond the initial set-up. Much thanks to Andrew for letting me borrow his Telrad (because I left mine in the garage back home) so I could do the initial alignment. And I also have to thank Renato for letting me use his barlowed collimator.

There were a few high clouds to the north and west but nothing that obscured our skies. The seeing was good, but not great (probably 6 or 7 out of 10), and the transparency was good, but not great as well (probably 7 or 8 out of 10). I was able to detect the Horsehead nebula (B33) against the reflection nebula IC 434 unfiltered in the 25", which is a pretty good indication of decent transparency. Of course, the view through the H-beta filter was much better. To quote Renato while he was looking at the Horsehead in the 25" "Now I can go home a happy man."
 

The early winter Milky Way was a bright and noticeable as I've ever seen it, with a bright swath and associated dark areas painted across the night sky from Cygnus thru Cassiopeia to Perseus. Tucson is about 50 miles north of the Las Cienegas observing site but still puts up a considerable sky glow. All evening long I was looking at the silhouettes of these mesquite trees against the sky glow of Tucson and reminded of images I've seen of acacia silhouettes against the African Serengeti plains. The image above has Cassiopeia just above the sky glow of Tucson.

I didn't have an observing plan, other than to re-familiarize myself with the night sky. I figured it had been almost 8 months since I last viewed through the 25". This was partly due to a weird travel schedule at work and the wetter than normal summer we've had in SE Arizona. For solar system objects, I looked at Uranus, Neptune, Saturn, and Mercury. Andrew and I also tried for P1/2006 (Levy) but weren't successful in trying to see the mag 12.2 object through the gunk low in the sky. I thought I had the latest orbital elements but I didn't so we had that going against us as well. I knew it was near Algorab in Corvus but that was little help.

I did the usual deepsky stuff: M51, M33, M31, M32, M110, M81, M82, NGC 891, NGC 253, NGC 4565, NGC 3628. Renato was trying to verify he was seeing the Bubble Nebula (Caldwell 11) in his 12.5" Portaball. By the way, Renato is one of those rare individuals who star hops his way to objects. And he does so quite successfully. The Bubble Nebula sits just off of M52. Andrew had NGC 2359 (Thor's Helmet, a.k.a. Gum 4) which looked absolutely spectacular. I looked at this in the 25" using the 17 Nagler and an OIII filter and saw quite a bit of detail in the nebula. This object is very large and completely filled the eyepiece. This was my most memorable object for the viewing session and one that I will make sure I visit in the future.

Andrew did a series of 1 minute exposures of Orion rising over the Whetstone Mountains on the eastern horizon of the observing field and made a very nice composite movie which you can see on his web site (www.siowl.com/index.html?thanksgiving). Not being nearly as skilled as Andrew, I settled for a quick "souvenir" photo of Orion. Actually, I took a series of 10 shots and was hoping that I could stack them to bring out some nebulosity in the region. The image above is a stack of 10 images, but I needed to go longer than 5 seconds for each exposure. You can move your cursor over the image to see the constellation stick figures.

I'm not sure if there was an "official" meteor shower around this night but there certainly was a fairly large number of meteors seen, sometimes about 1 per minute. We really couldn't discern a consistent radiant. Andrew pointed out a very nice meteor that probably resulted in a metorite landing in SE AZ or Western NM. I saw this particular  meteor when is was near Cassiopeia and watched it streak across the sky for 8 seconds or so until it diminished near Monoceros. It broke up into several pieces towards the end of the meteor show. Very impressive, and almost as good as the Peekskill meteor of 1992.

Renato left around 2 AM and Andrew stayed until just about 6 AM. It was a bit on the cool side with the last readout I saw from Andrew's temperature monitors on Deep Violet being 2° C. I was cold so I stayed in the truck and caught a few winks before tearing down and heading home around 7:30 AM.

Dawn over the Mustang Mountains

Here's a shot at daybreak of the observing "field" looking to the west at the Santa Rita Mountains. Mount Hopkins is the tallest peak, and also the site of the Whipple Observatory. The ranchers had kindly mowed the native grass leaving us with a nice observing field just off the abandoned runway.

All images taken with a Canon EOS 20Da with 24-70mm EF lens.

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