Monday, December 29, 2008

Planetary Alignment From Kitt Peak

Melinda and I were invited by David Harvey to join him over the weekend for his engineering/observing run on the 90" Bok Telescope of Steward Observatory at Kitt Peak. With the storm clearing late in the week, and our Whitewater Draw trip Saturday, Sunday was our only chance to overlap. Melinda had to work, but friend Laurie Larson wanted a chance for some photography, so she joined me for the trip. The 90" is shown in the foreground here from a previous KPNO visit. The "Bok Walk", a platform about 50 feet off the ground seen on the near side of the building in this shot was used as vantage point for all these photos.

Dave is a software engineer for Steward, so these runs occur occasionally, this run officially was to work on telescope collimation, but the other engineer called in sick, and the telescope was available for other applications. Dave had his own agenda, but graciously offered the scope to shoot an object two, and I took advantage of it. Dave is a professional photographer in Tucson (click on his blog link above!), and I picked up a lot in the few hours we spent together. The 90" images will be shown in a subsequent post. For the moment, I'm showing the planetary alignment that took place Sunday evening.

From Whitewater draw we spotted the Mercury/Jupiter alignment (see Saturday's post), and tonight, the moon was added to the mix. It was a spectacular late afternoon - about as clear as I've seen it from the mountain (where I worked for some years in the 80s). The Four Peaks area east of Phoenix showed almost no haze, a good indicator of the clarity. With the low sun blocked by an antenna, the shadows cast into the desert dust by intervening mountains forward-scattered to out viewing position. At the same time, the slightly asymmetric shadow of the mountain was cast into the sky to the east (since the 90" is on the north side of the mountain, the shadow is steeper on the left side. It would have been a perfect cone had we been a couple hundred yards to the south).


As it darkened, Jupiter, Mercury and the moon were easily visible, with Venus of course much higher and brighter in the sky. After taking this shot, I got distracted by starting an exposure sequence on the 90", but a subsequent check of the western horizon from the Bok Walk a little later showed the moon just about to set. Amazingly, as the moon set into the inversion layer (a common temperature inversion, common in Winter and observed visually as we climbed the mountain road earlier), the moon became wildly oblate and distorted from thermally induced refraction. It was an amazing sight and my favorite image of the evening (a 10 second exposure with the camera balanced on a cinder block wall!). Stay tuned for some shots through the 90" in one of my next posts!

2 comments:

Tuguldur said...

nice shots, especially the last one is terrific!

btw, did u see Dave's blog? he just put some crazy astrophotos with that big piece of class. Can't wait to see yours too.:D

Unknown said...

Dean & Laurie:

Thanks for the company on Sunday - always good to hang with fellow astrophotographers. Hope you got some good stuff through the big glass. BTW - Laurie left here NOAO jacket up here - I'll bring it back down to Steward when I leave. ~Dave