Thursday, July 8, 2010

Weekend Observing

Last weekend was the long holiday weekend, and with the monsoon rains still absent, Melinda and I headed out of town to take advantage of some dark sky observing both the day before the 4th and the day after. Moonrise was about midnight, but we were able to enjoy a couple hours of desert darkness each night before heading back to the lights of civilization. I wanted to photograph wide fields of the Milky Way, and Melinda wanted to take some closeup shots through a telescope, so I set her up shooting through the little Meade 80mm refractor. When we went out Monday night, I shot through the 14" plus Hyperstar, and she shot some wide fields. For this post, we'll cover a few of my favorites.

Joining us on the western slopes of Kitt Peak was a long-term visitor from Germany, Christian. We met him a couple months ago at an astronomy club event, and invited him to join us. He is quite the avid visual observer, packing a 16" telescope, so provided us some spectacular views while we took some pretty pictures. Here he was examining Venus in the still-bright twilight.

And while I posted a similar shot of the planetary conjunction in just our last post, here is one taken the night before from our darker observing site.

My favorite object might be the center of our Milky Way galaxy. I can just gaze at it endlessly with my mouth open in amazement. Just the thought that the cloudiness is caused by untold millions of stars, interrupted only by clouds of dust and gas is just amazing to me. It is relatively easy to image too - the wide shot at left is a stack of 9 - 3 minute exposures with a wide-angle 20mm lens. The greenish glow along the bottom is a bit of air glow as the horizon is just out of the frame. The bit of shadow in the lower left corner is the shadow of a tree that was barely in the first couple of frames... Otherwise the field is a mass of deep sky objects that serve as potential future photographic targets.

One of my favorite fields is just above center - the dark nebula referred by some as the "Prancing Horse", or the "Pipe Nebula". Regardless, the mass of dust clouds obscuring more distant star clouds is an amazing field, reaching across 30 degrees of sky to the red super giant Antares and the globular clusters that frame it. This shot is a stack of 8 frames of 20 minutes total exposure with a 50mm lens. Be sure to click on the pictures to load the screen-wide versions.

I'll wrap up this post with a view of southern Scorpius. On a good night from Iowa, the bottom arc of the Scorpion hugged the southern horizon. Because Tucson is 10 degrees of latitude further south, the Scorpion is raised by that same amount, so some of those objects are easier to observe. There is an object called the Cat's Paw Nebula also known by the less-glamorous name of NGC 6302. Shown at left here is another shot with the 50mm lens showing the full arc of the southern part of Scorpius, with the bright stars of the stinger at left. Just to it's upper right is the paw print of the nebula, glowing red because of the florescence of hydrogen gas. On our return trip Monday night, I shot it with the 14" telescope and Hyperstar lens (670mm, F/1.9)with 20 minutes of exposure. While I don't remember ever observing this object visually, Christian tracked it down for us, and we spotted one of the brightest "paw prints" through his 16".

All in all, between the picnicing on the 4th sandwiched between 2 nights of observing and 2 movies over the weekend ("Karate Kid" and "The Secret in their Eyes"), we were plum tuckered out and ready for the workweek to start to get some rest! The dark desert skies were the highlight for me - with the rains coming, it might be months before we get out again...


Astroweis said...

What amazing nights those were! My favoutrite visual observation was Abell 39 - a 13.7 magnitude planetary nebula with 15.5 mag central star, both of which were visible in the 16".
Hope for clear nights on this weekend.
See you!

David A. Harvey said...

Outstanding work Dean! My favorite target - Rho Oph! Bravo!

David A. Harvey said...

Outstanding images Dean! Nicely done! You captured my favorite object too - Rho Oph! Bravo!