Sunday, October 11, 2015

Seeing the Unseen!

I was up on Kitt Peak last evening, helping out with their beginning astro-photography class. It was a very nice group - one fellow who lives 25 miles from our house in St Charles, IL, a couple from Florida and even a couple from Tucson! All were fans of astronomy and getting into trying to image the sky. My little presentation was about some of the time lapse that I do. Of course, you can click on the "time-lapse" keyword on the right side of the page, or go to this link, which does the same thing!   My motivation for most of my time lapses is sort of seeing the unseen by demonstrating the motion of the sky or objects, instead of static images.

Last night, the second night of the workshop, we got them going exposing on they sky with their own equipment on tracking platforms or piggyback on the TEC 140 piggyback on the 16" scope at the Roll Off Roof. As first time astro-photographers, we ran into the usual issues - not having adaptors for all cameras, or not having the intervalometers or cable releases to take long exposures, but we got past them mostly. Most were truly enthused about their first images, and all seemed inspired to push forward into this new aspect of their hobby.

While we were away for dinner, I had set up my tripod-mounted XSi with a 300mm lens shooting at the VLBA telescope about a mile down the road near the picnic area. The 80 foot dish is part of a 10-telescope array scattered around the hemisphere. I was hoping to demonstrate how time-lapse techniques show things you had no idea were going on. Take an image of the dish and yea, looks interesting, but take a second and third and you realize that it is changing its pointing between EVERY frame taken at 30 second intervals! Of course, I knew nothing of the observing program - the telescope is run remotely from the VLA headquarters near Socorro, NM. I do know that IR and radio wavelength observations used to take data by offsetting off the object to measure the background signal. This is what appears to be happening here. You can see offsets both N-S and E-W in the time-lapse.

Anyway, I took the VLBA sequence and also one of the sun setting in a clear gap in the west, to demonstrate how easy it is to use Microsoft's Moviemaker program to make the time-lapse. But the constant motion of the radio telescope was more interesting in my book. However, the sunset was interesting too in that it set directly behind the Pinicate Mountains, visible as the more distant peaks here. They have been featured many times on the blog as we drive past them on the way to Puerto Penasco on the Sea of Cortez. At left is a pre-sunset image of where the sun eventually set. The flat-topped mountains are the Mesquite range, nearly due west of Kitt Peak. The more distant mountains are the volcanic Pinacates, just over 100 miles distant. At right is the same horizon with the sun entering the image...

Finally, here is the time-lapse I constructed during the workshop, here with an intro shot and uploaded to Youtube. The radio telescope is a flurry of activity, moving between nearly every frame taken at 30 second intervals.  Go to full screen and HD if you have a high speed internet connection!

We fought a few thin clouds through the evening, but fun was had by all as they say, and hopefully we all learned a few things.

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