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Sunspot AR2473, Christmas Visitors, Mercury, ISS

Posted: 27 December 2015

After photographing the Christmas Full Moon before sunrise on Friday, 25 December 2015, the sky became mostly overcast. Saturday, 26 December, dawned partly cloudy, with lengthy periods of nearly overcast skies. Some friends came over during the afternoon and evening. I opened the observatory so they could do some observing whenever clouds permitted.

Open: Saturday, 26 December 2015, 1331 MST
Temperature: 53°F
Session: 900
Conditions: Mostly cloudy, windy

Although you can't see it too well, I wore my "William Herschel, astronomer" apparel:


After opening the observatory I mounted the Orion full-aperture solar filter on the 8" telescope. I also attached the PST solar telescope piggyback on the telescope. Both are seen in this equipment photo. 1345 MST: slewed the telescope to the Sun (using the "Sun as Asteroid" technique). Unfortunately, the sun was behind the clouds. I waited a few minutes for a small hole in the clouds to move in to position. I had a brief look (about a minute) at the Sun through the 8"; the look was long enough to focus and grab this quick handheld iPhone afocal 83X photo:


The large sunspot group AR2473 is visible in the photo, as is a cloud. This is a cropped portion of the Sun photo above showing the sunspot group:


I was never able to view the Sun in H-Alpha through the PST due to the clouds. 1358 MST: gave up Sun viewing and put the telescope to Sleep. The rest of the daytime was mostly overcast so none of the vistors, who arrived after 1430 MST, were able to do any Sun viewing.

I was in and out of the observatory during the day and early evening to check observing conditions.

1740 MST: a few minutes after sunset the sky was partly cloudy. I returned the observatory, removed the solar filter and PST, checked Mercury in the telescope, 83X, and it was visible through a hole in the cloud cover. I switched to a magnification of 222X; the gibbous phase of Mercury was visible although seeing was lousy due to its low altitude in the sky and some thin clouds which frequently covered the planet. Fortunately, five of the visitors were able to see Mercury through the telescope before clouds completely obscured it. After seeing Mercury, most of the visitors returned to the warmth of the house, but one hearty soul stayed at the observatory with me (the temperature was 34°F). At 1759 MST we saw the International Space Station (ISS) during the last couple of minutes of a long pass overhead.

1900 MST: I finally gave up due to the clouds and began closing the observatory.

This was the Nine Hundredth session in the observatory since it saw "First Light" on 18 August 2009. On to my One Thousandth session in 2016!

Close: Saturday, 26 December 2015, 1905 MST
Temperature: 34°F
Session Length: 5h 34m
Conditions: Partly Cloudy

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