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ISS, Moon

Posted: 29 October 2014

Opened: Tuesday, 28 October 2014, 1741 MST
Temperature: 83°F
Session: 736
Conditions: Clear

After opening the observatory I immediately began preparing for the evening's excellent pass of the International Space Station (ISS). It would pass nearly through the zenith at a line-of-sight distance of 263 miles, which would provide a nice size for imaging at mid-pass. I updated the ISS TLE in the AutoStar, mounted the D7000 DSLR on the 8" LX200-ACF at prime focus + 2X PowerMate. Checked the finderscope alignment; OK. Focused on the moon and locked the focus. This image of the moon confirmed the focus (taken at 1/500sec, ISO 4000):


1756 MST: all was ready for the ISS pass. The pass would began after sunset but against a still bright twilight sky and would begin in the trees to the northwest.

1809 MST: pass began. Once I picked up the ISS visually it was obvious that the initial telescope pointing was way off. I slewed the telescope to get to the ISS and began HD video recording, 1/1250sec, ISO 4000. Tracking was pretty good. However, I did have to rotate the dome several times as the ISS approached the zenith. And I lost it at mid-pass as it went through the zenith. I did re-acquire the ISS in the finderscope past the zenith and tracked it until it disappeared behind the hill. When I slewed back to the moon (for more lunar imaging) I discovered that the focus had slipped, resulting in a slightly out-of-focus image even though the focus had been locked. The following image shows how good the images COULD have been had the focus not slipped:


I imaged the moon at prime focus + 2X PowerMate at 1/250sec and 1/320sec, ISO 1600:



This is a prime focus image, 1/640sec, ISO 1600:


1830 MST: ended lunar imaging and did some lunar observing, 83X.

Closed: Tuesday, 28 October 2014, 1851 MST
Temperature: 69°F

REMINDER: I will be at the 3rd Arizona Science and Astronomy Expo, 1-2 November 2014, Tucson Convention Center. I will be helping out at the Oceanside Photo & Telescope booth on both days. Stop by and say "hi".

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