Sunday, May 24, 2015

Saturday Star Party!

Tucson has been enjoying cool temperatures this Spring. While we normally break 100F about now, yesterday the high temp was only 79F, and with the blue sky calling my name, we planned an impromptu star party. As the Memorial Day weekend was ramping up, we decided to go up the Mount Lemmon Highway and set up a telescope to show people the crescent moon and planets that are up early in the evening. Members of the astronomy club could be seen doing that a decade or two ago, and it was fun showing newbies the sky - that was the plan anyhow!

We arrived at Geology Vista after 6pm, about an hour before sunset, and I set up the 14" Celestron. Living in the van, the telescope usually comes out of its crate pretty warm to the touch, so I had the secondary off to allow the tube to vent. We had a few folks stop by, but we weren't quite open for business. And while the scope was cooling, with temps in the low 60s and dropping, Melinda was bundled up, shown at left...





During this time, just before sunset, I took the opportunity to take some test shots with the William Optics 11cm APO that I also brought along. When doing closeups of distant objects, nothing beats a good APO, unless you want to spend upwards of $5,000 or more for one of those "football" telephoto lenses. The WO scope has a focal length of 770mm, so works well as a telephoto lens, or as a small telescope. My target is in the upper paragraph at right - an array of antennae located atop Mount Bigelow further up the road. According to Google Maps, it is about 5km (3+ miles) away from our location. That photo was taken with a 100mm lens, and at left is the view through the WO scope. The ultimate test though is the full-resolution image shown at right here. The image looks great - good sharpness and resolution down to the limit of the pixels...


About the time we put an eyepiece in the Celestron telescope, our friend Dick showed up. I had alerted him to the fact we would be setting up, and he was always a sucker to drive a few miles to look through a telescope or two. He put both the Celestron and WO refractor to work looking at the early evening objects. Unfortunately, even though he lives in Tucson and knows about elevation and cool temperatures, he showed up in shorts and sandals, so immediately grabbed a blanket out of my van to keep tightly wrapped around himself while we observed! Here, with the 17mm Nagler eyepiece, he was checking out the moon at 240X...

As you can see, we didn't have a huge line. All told, in the couple hours we were there, we had a big 7 viewers checking out the Moon, Venus and Jupiter, and one couple stayed late enough to spot rising Saturn.

Another photographic target is the lights of Tucson rising out of the twilight. While normally an amateur astronomer would get upset about the lights, Tucson is better than most large cities for at least enforcing some lighting codes keeping light out of the sky. Still, it is a pretty sight deep into the twilight, with the Santa Rita Mountains barely visible far south of Tucson to the left, and the Sierrita Mountains to the distant right. The headlights of a car coming up the Catalina Highway outline the road below us.

Finally, Dick came to the end of his patience, and since we were out of customers, I started closing up about 8:30. Packing up the WO scope first, I got Melinda's ok to spend a few minutes shooting a mosaic of the Moon. It only took a couple minutes to remove the diagonal and eyepiece, and substitute the camera adaptor and mount my canon XSi. Shown at left is the 3-frame mosaic (assembled w/Photoshop), at the largest I can show on the blog (1600 pixels high). Nothing outrageous resolution-wise - images looked a lot fuzzier than the visual view through the eyepiece. When viewed as a mosaic, it looks like a fine wide-field view.

After an uneventful ride back down the mountain, we were back home at 10pm - an early night, and a little disappointing with the lack of viewers, but a fun getaway...

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