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Moon, Comet C/2013 A1 Siding Spring

Posted: 1 October 2014

Opened: Tuesday, 30 September 2014, 1809 MST
Temperature: 85°F
Session: 723
Conditions: Clear

1811 MST: sunset. Began observing the moon at 1816 MST using 83X and 222X. There were some fascinating sights along the terminator, as is usually the case near First Quarter. Mounted the iPhone 5s on the 8" LX200-ACF using my modified MX-1 Afocal Adapter. This is afocal 77X:

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Some sights along the terminator, afocal 154X:




1837 MST: powered on the GC Wi-Fi Adapter and used SkySafari Pro 4.1 to GOTO to Comet C/2013 A1 Siding Spring. It was currently Azimuth 193° and Altitude 16°. 1840 MST: some stars were visible in the 83X eyepiece field-of-view but no comet was seen. Began preparing the D7000 DSLR for comet imaging just in case. 1900 MST: more stars visible but still no comet against the still bright sky (twilight and moonlight). 1911 MST: still no comet visible. Decided to start imaging anyway. Did a focus test on Antares using the Bahtinov Mask. SYNCed the AutoStar on Antares. Did a 30 second, ISO 1600, prime focus image. The comet was not obvious on the camera LCD. Did a 30 second, ISO 2500, exposure. This time the comet was obvious in the image. I took an exposure every 5 minutes from 1920 MST to 1950 MST. After the first image I slewed to the moon to adjust the focus. Since the comet was so low in the sky the images were all somewhat blurred. But I captured Comet C/2013 A1 Siding Spring as it is heading towards its rendezvous with Mars on 19 October 2014. This image was captured at 1920 MST showing the comet near the center:

Mouseover or tap on image
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The image is inverted. The comet's motion is actually northward heading towards Mars.

1951 MST: finished comet imaging. Unmounted the camera and tried to view the comet, 83X. Still wasn't visible. The moonlight interferred and the comet was now much lower in the sky. My next viewing/imaging opportunity likely won't be until this Friday.

Closed: Tuesday, 30 September 2014, 2010 MST
Temperature: 67°F

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