Saturday, June 11, 2016

Grand Canyon Star Party, 2016!

This week was the 26th Grand Canyon Star Party... Tonight (Saturday, 11 June) is the last night, but with my schedule, I was only able to attend 3 nights through the middle of the event. Melinda needs to have someone around to assist her, and our friend Donna graciously offered to stay to allow me to keep my attendance streak alive. I'm the only observer to attend every year of the event, in fact, I've done 27 as I was there for the zeroth version, when my new bride, first wife Vicki and I first honeymooned there and decided to come back for our anniversary with some friends to hold a public star party at rim side. Other than pushing the date back to June (froze our butts off on the first one held on our actual anniversary in early May), the event continues today!

So Monday morning (6 June) found buddy Roger and me wheeling our way towards the Canyon. Now over the decades, things "happen". There was the rear wheel blowout a few years back, and in an early year I had radiator issues in my old-old van before getting "Old Blue" in '94. So breakdown issues are always on my mind. It wasn't really a surprise when we stopped in Phoenix for a quick bathroom break and the "new" van wouldn't start to continue the trip. The resultant clicking sound indicated an electrical issue, and sure enough, there was some battery corrosion, but my tool collection was little prepared for the weird battery terminals.n Fortunately, Roger is an AAA member, so help was on the way in minutes and in short order, "Kevin" had tested the system and recommended a battery replacement with 6 year guarantee, and we were on our way again. No other misadventures occurred, but we got in a little late to the campground and after plopping the tents down, headed to the observing site. It appeared there were plenty of scopes, so we didn't feel guilty not setting up the first night, but instead walked out to the rim to see our first view of the canyon at right, just a little before sunset. Roger hadn't been there in about a decade, so after a quick inspection, headed down to the observing field to rub elbows...

We immediately ran into lots of acquaintances as the astronomers tend to re-attend from one year to the next. While the Tucson Amateur Astronomy Association sponsors the event, the astronomers that volunteer to set up their scopes for the public are from all over the country - perhaps 60% from Arizona, but many from California, Texas and elsewhere. The organizer Jim O'Connor clams we had astronomers from England and France too! There were some thin clouds hanging around after sunset, and we gathered to chat as they hung around. Shown at left is a group of us, starting from left Doug Taylor-Gebler, Joe Bergeron, Roger Ceragioli and Bernie Sanden, with George Barber at far right. While the clouds might normally have affected the observing, this year, with a trio of bright planets (Jupiter, Mars and Saturn) visible from sunset, as well as a waxing crescent Moon, these clouds affected observing little. Once the observing started in earnest, I captured the view at right in a 20 second exposure with the new 6D and Samyang 14mm lens. In it, Bernie's 12" is pointed at Saturn at center near the horizon, with other star party action in the background.

After a little more visiting with friends, Roger and I decided to retire a little early after our long day of travel, so headed "home" to camp. We tried to stop at Yavapai cafeteria, newly remodeled, but couldn't find the snacks we were looking for, found the general store closed, so headed to the tents. Once in camp, it appeared completely clear, so sat and gazed upwards for a bit. There is a curious illusion with the trees blocking the lower part of the sky where light pollution usually exists, that makes the sky appear darker than it actually is. I didn't take any comparison shots from the observing field, but broke out the venerable Nikon 16mm fisheye. Finally with the full-frame sensor of the 6D, I got back the full 180 degrees corner-to-corner field of view I used to enjoy with film. North is generally up, the Big Dipper dominating the upper part of the field, with Arcturus just below center and brilliant Jupiter at far right. Unfortunately Mars, Saturn and the center of the Milky Way weren't high enough to appear, and we weren't about to stay up much later, but the 30 second exposure is pretty impressive!

Surprisingly we rose early Tuesday morning, and hit Yavapai cafeteria for a mediocre breakfast and then continued out to the original site of the star party at Yavapai Point. I was interested in revisiting where I spent many happy days showing magnified views of the Canyon to visitors to attract them to the evening's observing. This time it was a test of optics and camera as I used the Canon 6D with the TEC 140 telescope and field flattener corrector lens for the first time. One of the favorite places to point out for people was the beach down by Phantom Ranch Campground where the river rafters would pull up for breaks. With the 20X binoculars I used to use, hikers and rafters could easily be spotted, about 3 miles away and a mile below us. Nearby is a turn in the South Kaibab Trail where hikers can usually be seen. In a moment of inspiration, I took a 6-frame mosaic, easily assembled in Photoshop, but how to display the 16,000+ pixel wide image in a blog that limits images to 1,500 max, still showing some details visible in the original? I decided to show the mosaic in low resolution, but a few scenes at full res, the resultant view shown at left. Even at 10am, seeing was a limiting factor, but overall sharpness was quite good - can't wait to get it under a dark sky looking upwards.
Unfortunately, the chance to try the TEC at night never materialized. At the star party, you are frantically busy with visitors till some moment between 10 and 11pm when they magically disappear. While this would seem a good time to do some imaging, this is when the astronomers sweep in with their vehicles to pick up scopes and even with parking lights would disrupt an imaging session. Better to play with gear without a group around! I did have a brief window to shoot the 6D with the venerable 70-200 Canon zoom. With the smaller APS sensor of the XSi camera, it always performed admirably. But how would it work with the 6D's sensor over twice as large? That is what I hoped to find out. After the public left Tuesday night, I mounted the camera on the bracket atop my C-14 scope for some tracked shots. As predicted, cars were coming in to collect their gear, but got a couple shots. First up was the wide shot at left taken at 70mm focal length showing Scorpius with Mars at left and Saturn at upper left center. Immediately it was seen the C-14 tube was blocking part of the view! It had never been an issue with smaller sensors but it was for this camera... This shot is a single 60 second exposure at ISO 3200 at F/3.2 - pretty amazing for the field shown! Zooming in to eliminate the tube obstruction, I took a few frames of the narrower field at right at 105mm focal length. This is a stack of 4 frames of 2 minutes each, so 8 minutes total exposure. We miss Mars in this view, but the nebulosity around Antares is easily seen, as is Messier 4 to Antares' right, as well as the dark nebulosity headed towards the "Prancing Horse" in Ophiuchus. Looking carefully at the dark clouds you can pick out the majority of the Pipe Nebula at bottom and the Snake Nebula a little above it.

Fortunately, there are a LOT of pixels to combine when making a 1600 pixel wide image for the blog. The camera puts out an image nearly 5,500 pixels wide, and if you look at the image at full resolution, the corners look pretty lousy! Shown at left is a full-rez crop of the above image at left. While that image looked just slightly bloated, at full scale, the coma and defocus is apparent. While you might decide that the lens isn't suitable for imaging any more, I've got to look into where in the field to focus. I believe I focused at the center - focusing closer to the edge might give better overall images for a final result.

Those were the only night-time images taken. The several hours of public observing grinds on you and you don't really feel like staying too late as the sun hits the tent early in the morning! Life in camp was fun... Roger and I typically ate out at Maswick or elsewhere, so didn't waste effort packing food, cooking utensils, or time and effort to cook. We did have lots of camp "visitors"! The last few years elk have been common company and every day they would cruise through camp feeding on the young oak leaves they desired. This one was a young female, but still was reaching a good 8 feet up into the trees for the right leaves. She seemed unconcerned of our presence - a few minutes after the image at left (taken with 300mm lens), she walked right behind Jose from San Diego! Jose was trying to take a selfie with his phone, but while watching it live, forgot to push the button for an unforgettable shot!

We needed to head back early on Thursday after 3 nights there, two while set up observing for the public. With the crescent Moon as an early target, I'd usually set up on that at 240X or so - bigger than most astronomers ran their scopes. As it got darker and everyone was on the moon, or Jupiter or Mars, I'd move to M-13 where 120X or so did amazing things to the globular cluster. Later, I'd often re-show the moon to those that missed it earlier, usually to great fanfare! There were many memorable meetings with the public, not only Americans, but from all over the world Just the last night we had observers from Argentina, Guatemala, Finland, Egypt, Serbia, and from all points of the U.S. The event has grown steadily from the first one in '91 when me and 3 friends from the Tucson club set up for the public. It is now a big deal with hundreds of astronomers over the course of the week and several thousand public visitors every night. After years of Park effort, the International Dark-Sky Association awarded the Grand Canyon National Park provisional "Dark Sky Park Status" where the night sky will be protected by controlling lighting to minimize pollution, assuring that visitors will continue to join us and stare in wonder at the Milky Way transiting overhead every June. I'm gratified that this event has stimulated interest in our dark sky heritage, and hopefully will continue long into the future! Think about coming to join us!

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