Friday, February 6, 2015

The Topic Was Comets!

Tonight was the monthly meeting of the Tucson Amateur Astronomy Association - the first Friday of the month over at the auditorium of Steward Observatory, our regular location. With the recent appearance of Comet Lovejoy (C/2014 Q2) in our skies we had a couple speakers, both of which could be considered Tucson's "Mr Comet". Shown in the image at left, Jim Scotti is at left, and David Levy at right during their Q&A session. Jim has been working with the Spacewatch Program on Kitt Peak since he was an undergraduate in the early '80s.  David is an author and comet hunter who located to Tucson for its clear skies in the '70s. Between the 2 of them they have discovered over 30 comets (!) and both are experts in the searching for, care and feeding of comets. David, with a background in English literature, talked about some of his experience in discovery and mentors, including well-known amateur and author Leslie Peltier, who inspired him greatly. Jim talked a little about his work with Spacewatch, and also showed an image or two from the Rosetta spacecraft, currently in orbit around Comet 67P/Churyumov-Gerasimenko. It was fun and informative to have the tagteam speakers.

Then it was time for a showing of some of the photographic efforts of clubmembers.  We had something like 6 or 7 different members and skill levels and equipment shown.  Besides my image of it passing the Pleiades a couple weeks ago, I showed one from last night!  I've not had a chance to post about that trip yet, so am adding it here. 

Last night (Thursday, 5 February) was the first chance after full moon where there was about 40 minutes between the end of twilight and the gibbous moon rise.  I headed out towards Kitt Peak and shot it from the base of the mountain along highway 86.  As for the Pleiades shot, I used the Vixen Polarie tracker, the Canon XSi camera, and this time, another film-era lens - a Nikon 135mm F/2.8, stopped down to F/4.  Shown at left is the combination of 5 exposures of 4 minutes length, and stacked in Nebulosity.  While the comet is still visible to the unaided eye, it is definitely fainter than my last outing on 19 January.  In binoculars the fuzzy cometary appearance was unmistakable, but the tail was also fainter, and only hinted at, not directly seen like in January.  But photographically, it still looked good!

The comet's blue ion tail stretches nearly 10 degrees across the entire frame. But there are a couple other subjects of note in the field. Just a day or two earlier it had passed very close to the bright star at right - Gamma Andromeda, also known by its Arabic name Almach. Telescopically, it is a beautiful yellow-and-blue double star. Also easily seen in the view is a nice star cluster, Messier 34 down in the lower left. But probably the telescopic highlight of the field, one of the reasons I went to some effort to capture it, is the quintessential edge-on galaxy NGC 891 at bottom center. In a decent-sized telescope (something in excess of 12" or so), it is truly spectacular. While not quite spectacular here (be sure to go to the link to see some great images), at least it is recognizable at the telephoto-lens scale too. The image at right points out the galaxy to make sure you don't miss it.

I had also thrown together a 15-slide Powerpoint of some of the bright comets in the last 8 or 9 years, most all drawn from the blog that seemed to be well received.  Hopefully between our speakers and some of the images, more members were inspired to get out and shoot more of some of these objects, which still mesmerize me after nearly 50 years of observing them!

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