Wednesday, December 29, 2010

More Sunset Fun!

We certainly hope that all of our regular readers (all 5 or 6 of you!) have gone to Youtube and checked out the spectacular sunset alignment video we posted way back 10 days ago. Partly because of that success, we got to repeat the sunset trip several times, setting a record of 4 attempts this season!

Adam Block, who runs the SkyNights program on Mount Lemmon had a large group going up for the lunar eclipse on the 20th. Unfortunately, while we had some views of the sun while we set up the 5 telescopes (!), the sunset was totally socked in, and other than the view of Kitt Peak telescopes, the group of 25 people were skunked on the sunset observing. At least we tried! I think they had at least partial success on the lunar eclipse observing like we did in town...

Our next try was on Christmas eve the 24th. Friends Tom and Jenn came down from Phoenix to join in the fun with at least 3 other TAAA members. I was thinking that the only way we could improve on our sunset video from the 18th was to do it in the light of Hydrogen Alpha, using a special filtered view that normally shows dramatic activity in the light of a primary hydrogen reaction. When you see images of the sun showing large flame-like structures off it's edge (called prominences), it is likely an Halpha image. Tom is about the only person I know with such a setup, so we supplied Melinda's camera for another video, and he supplied the scope and mount for the partnership. He also shot some white-light shots with a telephoto and through his 10" telescope.

The attempt was partly successful for us. There was indeed a nice prominence that was visible that was just about the last part of the sun to set, but because we needed to use a diagonal in the filter train, the video is flipped left-to-right. Rather than show an inverted video, we show some individual frames here that we flipped in Photoshop. To show the prominence, the disk needs to be overexposed some, and it is hard to coax good views of the prominence so low to the horizon, but I think we did ok (barely visible at the top of the frame). Everyone in the group was successful, even though we were once again shooting through some thin clouds in the west. First timers Jim and Susan O'Connor even had one of their images picked as the solar astronomy picture of the say!

Tom and Jenn stayed the night at our house (we dined on crock pot chili that was waiting for our return from the sunset), setting up Tom's 10" to look for the storm on Saturn in the early morning hours. Unfortunately, the atmospheric seeing was so bad, we could barely tell that the planet had rings!

About the time they took off for Phoenix at noon the next day, another friend Laurie arrived (another Phoenix refugee). She was also interested in the sunset alignment, so we headed up once again. Unfortunately, we were shooting through thin clouds again, and while the video was fine, the blustery wind we had was really shaking the mount, almost inducing motion sickness watching the movie! With the clouds we had more spectacular colors, and we paused at another pullout on the way down to watch the city lights come up against the dimming twilight. Laurie had a great time documenting it all.

So for this December 2010 solstice sunset season, we were 3 successes for 4 attempts. The alignment seems perfect - that pullout at milepost 8.7 seems the perfect place to be when the sun reaches -23.40 degrees declination. It was interesting that none of the 3 "clear" sunsets were actually perfectly clear, but we had great views of each anyway. And even though we got that perfect video on the 18th, well likely do it again a few times next year!

1 comment:

David A. Harvey said...

What fun! Great story. Congrats to all the sunset photographers!