Sunset Sky, Sirius, ISS,
Comet 41P/T-G-K, NGC4565 Needle Galaxy
Posted: 27 March 2017
Sunday morning, 26 March 2017, an Arizona high school principal visited Cassiopeia Observatory. The school is planning to purchase a SkyShed POD MAX and he wanted to see a POD up close to check out the quality. I gave him the complete tour. He was impressed with the SkyShed POD design and materials.
Open: Sunday, 26 March 2017, 1819 MST
Conditions: Partly cloudy
Although the clouds might interfere, I decided to open the observatory anyway as there was to be the best pass of the International Space Station (ISS) in several months and I wanted to try to photograph the Space Station.
1843 MST: sunset. Thin clouds were now in most of the sky. 1846 MST: took this photo of the observatory and the western sky using the D7200 DSLR:
1848 MST: the star Sirius was visible through some clouds. This D7200 DSLR photo shows the bright star near the center:
1856 MST: my little packrat friend tried to enter the open observatory door but when he saw me he changed his mind. I closed the door.
1900 MST: I relaxed on the recently added observatory patio bench before powering on the telescope for the ISS pass.
1912 MST: LX600 ON, StarLock OFF, High Precision OFF.
Slewed the 12" telescope to the star Procyon and SYNCed the AutoStar. I then updated the ISS TLE in the AutoStar. Next, mounted the D7200 DSLR at prime focus, focused on the star Procyon using a Bahtinov Mask, and locked the primary mirror. I then checked the finderscope alignment; it was OK. As this ISS pass would cross the sky near the zenith I moved the dome onto the PZT. 1930 MST: ready for the ISS pass.
I then looked towards the western sky. Venus may no longer be visible in the west, but the planet Mercury has taken its place as a bright planet low in the western sky after sunset.
1936 MST: turned on the shortwave radio to get WWV time signals on the DSLR video recording. I tweaked the focus of the telescope. 1939 MST: all was ready for the ISS pass to begin at 1944 MST. Using the D7200 DSLR I recorded the ISS using HD video, 30 fps, 1/1600sec, ISO 2500. The pass started a little earlier than the AutoStar had calculated and so satellite tracking was not very good, making it difficult to keep the ISS centered in the finderscope. In fact, I lost the ISS out of the finderscope field-of-view several times. And, as it turned out, I should have used a shorter shutter speed since the ISS was so bright at mid-pass (magnitude -4) that what images I did get of the Space Station were overexposed. But here are images from four video frames near mid-pass showing the station with its solar panels:
1953 MST: there were still thin clouds in the sky, but I began setting up to image Comet 41P/Tuttle-Giacobini-Kresak with the 12" telescope. Mounted the DSLR at prime focus + focal reducer. Then moved the dome off the PZT and back onto the POD wall. 2008 MST: Wi-Fi ON. Used SkySafari 5 Pro on the iPhone to GOTO Comet 41P. StarLock ON. Did some framing test exposures. 2020 MST: Wi-Fi OFF. Began a series of StarLock autoguided 1 minute, ISO 6400, White Balance 3570K, exposures every 5 minutes for 20 minutes. This is the first image of Comet 41P:
And this is five exposures made into an animation showing the comet's rapid motion in 20 minutes:
2043 MST: StarLock OFF. Ended comet imaging. At times StarLock autoguiding was not very good, likely due to the thin clouds.
Slewed to NGC4565 (Needle Galaxy). I debated whether the seeing (and hence autoguiding) was good enough for imaging the galaxy. I gave it a shot. 2051 MST: StarLock ON. This is a StarLock autoguided (although not precise), 5 minutes, ISO 6400, WB 3570K, image of NGC4565 (Needle Galaxy):
Two other smaller and fainter galaxies are visible in the image: NGC4565A (upper left) and NGC4565B (lower left). I will re-image NGC4565 on a future session.
2113 MST: StarLock OFF. Ended imaging due to the poor seeing.
2117 MST: viewed Comet 41P/T-G-K using 12x50 binoculars. The comet's coma was larger this night than it was a few nights ago, but the comet was still faint.
Next, viewed NGC4565 (Needle Galaxy) in the 12" telescope, 102X. Fairly nice view with some detail visible.
The last object viewed this night was Jupiter, 102X. Cloud bands and the four bright moons were visible.
2128 MST: LX600 OFF.
Close: Sunday, 26 March 2017, 2137 MST
Session Length: 3h 18m|
Conditions: Clear with some thin clouds
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Copyright ©2017 Michael L. Weasner / email@example.com
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