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Mars, Venus, & Comet 45P/Honda-Mrkos-Pajdusakova (sort of)

Posted: 30 December 2016

Tuesday morning, 27 December 2017, I went to the observatory to apply some more sealant to the join on the primary dome:

photo photo

Hopefully that will prevent the minor leak I saw at the base of the dome during a recent rain.

The sky become mostly cloudy by mid-afternoon on Tuesday, wiping out that evening's opportunity to observe the eclipse of RW Tauri, a binary eclipsing variable star. My next opportunity will be on Saturday, 7 January 2017, with mid-eclipse at 1930 MST. Another approaching storm kept the sky cloudy on Wednesday, 28 December.

As sunset approached on Thursday, 29 December, I decided to go to the observatory to try to photograph Comet 45P/Honda-Mrkos-Pajdusakova. I did not use the telescope or even open the dome due to clouds and strong winds that were blowing.

Open: Thursday, 29 December 2016, 1824 MST
Temperature: 58°F
Session: 1056
Conditions: Partly cloudy, windy

Equipment Used:
D7200 DSLR

1829 MST: using the Vortex 12x50 binoculars I began searching the southwestern sky for the faint Comet 45P/Honda-Mrkos-Pajdusakova. 1833 MST: with the assistance of SkySafari 5 Pro on my iPhone 6s Plus I located the comet. Only the head of the comet was visible as a small faint fuzzy object; no tail was visible.

I then began preparing to try to photograph the comet using the D7200 DSLR. I mounted the camera on a tripod outside of the observatory and began taking photographs at various exposure settings. I never saw the comet as a naked eye object. And due to the skyglow from Oro Valley, some clouds, and the comet's low altitude in the southwestern sky, the sky was never dark enough to capture the comet's thin tail in the photographs.

This is a f/3.5, 10 seconds, ISO 2500, White Balance 4000K, FL 18mm, photograph of the sky and the observatory:

Mouseover or tap on image
Mouseover or tap on image for labels

The observatory was illuminated during the exposure using a red flashlight. Mars and Venus are visible, as is a reflection of Venus on the observatory dome. The comet is not easily seen in this small photo, but its position is labeled in the rollover image.

1903 MST: ended sky photography due to the clouds and comet's low altitude. The comet head was still faintly visible in the 12x50 binoculars. This might have been my last chance to photograph the comet for awhile due to approaching storms and an increasing Moon.

1909 MST: SYNCed the observatory clock to WWV, and then closed the observatory for the night.

Close: Thursday, 29 December 2016, 1910 MST
Temperature: 56°F
Session Length: 0h 46m
Conditions: Partly cloudy, breezy

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