For the third year, our Astro 9 class journeyed to the Panoche Hills above Mercey Hot Springs for a night of dark-sky astrophotography (the turnoff a half mile beyond the hot springs is shown here). For the second straight year, however, we had weather challenges which took a toll on our attendence and results - a weak cold front was scheduled to come through at prime photography time. Forecasts said no clouds, but they were clearly wrong as late Friday afternoon wore on. Our newbie students bailed out, and even veteran Astro 9er Jonathan C. turned back after driving down most of the way. That left me and astro 9 lab assistants Karl and Shahram, and long time club member Stephanie V. I arrived shortly after sunset, and a bank of thick clouds was slowly migrating down from the north. The cold front made for a stiff breeze and after futzing around for 15 minutes, I decided to set up our gear down the sheltered side of the hilltop site, amidst the "resinous" (thanks, Stephanie, for the lurid plant descriptions!) tar weed and pungent turpentine plants.
As twilight faded, the moon was scarely half a degree from the cresent moon, but clouds overtook Scorpio during the shooting. Stephanie arrived shortly after me and set up the binocular to enjoy the beautiful view of the moon halfway between Antares and Tau Scorpii. I tried to get a sharp foreground horizon and with the electronic viewfinder couldn't see how soft that made the focus on the moon and Antares - sorry!
Clouds soon overtook the entire sky. Stephanie and I set up the GM8 and did get off a couple of guided film shots, but then just settled in and hoped for the best. Karl then arrived, and later Shahram. We set up our chairs, fired up the stove and kept up a steady supply of hot tea and hot chocolate while we all shared stories and got caught up on the latest with Steph while keeping an eye on the sky. Karl had his cell phone and called Tom, who checked the satellite weather. The forecast called for a thick band of clouds 200 miles wide, then a clearing, and then another band. Clear skies were expected to come in a few hours after midnight. By 2am, we were fading out. Karl said goodbye, and the rest of us got some sleep. At 3:30am, after one 90min sleep cycle, I awoke to clear skies and got up to finish the setup for doing some guided shots with the ST2000XCM on the GM8 mount. Shahram took a good half hour to emerge from his van. And, it took me an hour, stumbling around with my bad hip on the gopher-holed slope in the breezy cold conditions to get the CCD ready for imaging. Stephanie, after an initial spurt of energy, plopped back into her warm new sleeping bag. That's her - the lump in the background as Shahram sits in front of my laptop while it integrates on the Horsehead Nebula. I couldn't get the camera to calibrate in the Y direction - I hope just a balky connection. Still, I got a final image which is pretty nice. It was shot with the SBIG ST2000XCM: a stack of 4 x 5min images, each dark-subtracted at -30C below ambient. The final 5min image was in noticable twilight. The frames were single-shot color processed, then stacked in Registax v.3. Then a low-pass wavelet filter further smoothed the nebulosity. Finally, the brightness, contrast, and color saturation was tuned up in Photoshop by Shahram.
In the morning, a leggy local resident wandered by and obliged for some poses. I got down eyeball to beady eyeball for the shot at left, and repostioned the little guy on my purple RAV4 hood for more shots.
We fired up the stove for some coffee, hot chocolate, and tea, added some donuts and took in the view. The scene below is towards the northeast, over the central valley. Our 2100 ft elevation site is above the inversion layer and the air was crystal clear.
After some breakfast of coffee, hot chocolate, tea, and donuts, we escaped the sun in Shahram's van and did some initial image processing of the ST2000XCM images.
On the drive back, I stopped at the hot springs and got a flyer, and snapped this picture. There are trees, camp spots, a 7 gal/min flow of hot water out of the mountain, and tubs for relaxing.