I definitely needed a get-out-of-town adventure this summer and this was it. But the first couple of hours were miserable - bumper to bumper traffic from Santa Cruz all the way to Manteca and the Central Valley. On a thursday! Get me outta here! By the time I got to Oakdale it was better, and reaching the upper elevations of Yosemite I'd fully recovered from the effects of civilization. My planning page is here, and the Barcroft Lab information page is here. A magnificent sunset in the Yosemite high country started the photography off well.
First night was camping off the beaten path, overlooking Mono Lake. Weather was near perfect, with just a few cirrus. After the traffic nightmares, I didn't arrive and get my first images started until 11pm though. The 27% waning moon was to rise over Mono Lake at 12:54 am, so I could only get a deep set of images on a single object. I chose the Gamma Cass nebulae. Gamma Cass itself is a strong UV emitter and has a strong stellar wind which has sculpted the H-alpha emission nebula at the bottom and blown away most of the hydrogen from the blue reflection nebula above. Many of the earlier images in the sequence were marred by light cirrus, which increased the apparent size of Gamma Cass.
Gamma Cassiopeiae Nebula. 17x5min stack, chip T=-29C. Several of the exposures were affected by light cirrus which extended the halo around Gamma Cass itself. Levels, unsharp masked in Photoshop 7. |
The star over the moon is El Nath (Beta Tauri), the 5th brightest start that can be occulted by the moon. One month later, a spectacular graze of this star came through the San Jose area. |
My observing site above Mono Lake. |
Hot Creek, near Mammoth Lakes. Alas, I found it had been closed to bathers all summer due to increased geothermal activity. |
Moonrise over the lake was beautiful. Next morning I fixed some breakfast, packed up, and drove to Mammoth Lakes where I spent the late morning riding herd over my investment portfolio via WiFi, and rubbed elbows with the rich and high disposable income set at the New York Deli and Bagel in the Village at the base of the ski lifts. Onward, I stopped at Hot Creek (closed, unfortunately), and then to Convict Lake for a quick swim. Then on to Bishop and the Mountain Light Gallery, home to the work of famed wilderness photographer Galen Rowell. I'm amazed not only at the drama and spirituality, but at the technical quality of his images, especially as they were all done with color film. Before leaving Bishop, I made the BIG mistake of filling up at the Paiute gas station. Very cheap, and my engine was knocking like never before. I added some premium 76 gas 15 miles later in Big Pine, but it still didn't feel like it would make it up 12,500 ft to Barcroft Lab, and I turned around and bought a bottle of anti-knock additive. After 10 miles, it started sounding better. I made it to the Bristlecone Pine Reserve at 10,000 ft just in time to catch the setting sun on a magnificent bristlecone.
After sunset I returned to Grandview Campground and found Chris Kitting and we set up our scopes for a night of astrophotography.
Galaxy M33. ~12x5min stack, from Grandview. This image shows the danger of doing reductions in a hypoxic state. I dark subtracted and flat-fielded the component images while carrying on a conversation with fellows at Barcroft Labs after 3 all-nighters and at 12,500 ft. I subtracted the wrong dark frame - using the -35C frame instead of the -29C frame, meaning I only subtracted about 40% of the noise I should have. You can see the strong color speckle'ing which remains. I'll see if it's possible to add back the wrong dark and then re-subtract the right one. |
The Bubble Nebula and open cluster M52 in Cassiopeia. 11x5min stack on from Grandview. The individual frames had an alarming amount of color speckling. Why? enhanced cosmic rays at high altitude? But the 55 minute stack reduces this greatly. Rotated, cropped, unsharp masked, curves, brightness and contrast adjusted in Photoshop 7 |
The Snake Nebula in Ophiuchus. 9x5min (45min) stack at Tchip=-29C from Grandview. Again, an unusual amount of color speckling. For this one I used Photoshop CS2's de-speckle to minimize. Low altitude and less attention to clamping the camera in the draw tube, led to a tilted image plane and soft focus towards the bottom. Cropped, 'smart sharp', levels in CS2. |
The Plieades. 11x5min stack at Tchip=-29C from Grandview. CS2 Levels, Despeckle, 'Smart sharpen'. Saturation +6, AstroActions: smaller stars, deep space noise reduction. Comparing to the ECU star field, the faintest star on ECU is m=15.1, and this one is quite easy to see. I estimate the limiting magnitude is about m=18. |
The Heart and Soul Nebula (IC 1805 & 1848) in Cassiopiea. It looks to me more like the "Heart and Sole", with the tennis shoe shaped nebula at left (what does a soul look like anyway?). 12x5min stack at T=-35C from Barcroft Labs with ST2000XCM and Zuiko 100mm lens at f/4.5. Levels, "smart sharp", unsharp mask in Photoshop CS2. The stars showed a noticable core/halo structure, due to lens imperfections. |