Weather Update, Star HD7924 in Cassiopeia
Posted: 18 September 2015
Monday, 7 September 2015, was partly cloudy with minimal rain chances during the day. So I decided it would be a good day to apply some new sealant to replace sun-dried sealant at the observatory dome pivots. The sky became mostly overcast as sunset approached, with increasing rain chances over the next several days and nights from moisture streaming in from Pacific Hurricane Linda. Tuesday morning, 8 September, had a brief monsoon thunderstorm but only a little rain (0.02" on both the Netatmo rain gauge and the newly added NWS rain gauge). Thursday, 10 September, had 0.15" rain from a nearly all-day drizzle. Cloudy skies continued until Friday morning, 11 September, when the sky cleared. And with a forecast of a clear night, my hopes were high for opening the observatory. Unfortunately, clouds began appearing mid-day and by sunset the sky was mostly cloudy. Late Sunday afternoon, 13 September, got a surprise thunderstorm with lots of wind and thunder but only received 0.06" rain. Monday dawned clear, with a forecast of possible clear skies that night, unless our winding down monsoon had other ideas, which it did. Cloud buildups began appearing late morning, and as evening approached the sky was mostly cloudy. Tuesday remained cloudy but had a pretty sunset as I arrived at Oracle State Park for a meeting:
Wednesday, 16 September, dawned mostly clear, and a forecast of a clear night once again raised my hopes of being able to open the observatory. But by mid-day the sky was mostly cloudy. It did clear up overnight but I missed it. Thursday, 17 September, dawned clear but of course, clouds began appearing mid-morning. Such is our monsoon season weather pattern. However, the sky began clearing up as sunset approached so I decided I would open the observatory to do a few things. It would a short session due to a very early morning commitment on Friday.
Open: Thursday, 17 September 2015, 1807 MST
Conditions: Mostly clear
1819 MST: viewed the Moon, 83X. Then made an adjustment of the JMI MicroFocus; it had rotated slightly from its preferred mounting position. Once the correction was made, the MicroFocus worked properly again.
Switched to the Baader Zoom 8-24mm Eyepiece and viewed the Moon. The crescent Moon was already slightly too large to fit in the field-of-view at 83X (24mm) as the Moon is approaching its "Super Moon" orbital position the night of the Total Lunar Eclipse later this month.
1830 MST: sunset. View of the Moon at 250X (8mm) in the Zoom Eyepiece was very nice. Some excellent details seen. Then mounted the D7200 DSLR at prime focus of the 8" LX200-ACF and took this image, 1/250sec, ISO 1000:
1843 MST: removed the camera and viewed Saturn with the Zoom Eyepiece. Saturn was low in the southwestern sky but the view was still pretty good. At 250X some cloud bands and Cassini Division were visible.
1855 MST: did some more lunar observing, 167X (Zoom Eyepiece, 12mm).
1901 MST: Began re-doing the One Star Polar Alignment. 1912 MST: alignment and confirming checks were completed.
Then viewed the star HD7924 in the constellation of Cassiopeia, 83X. This +7.2 Magnitude star 54.8 Lightyears away was recently discovered to have three "Super Earths". I had planned to image it a little later in the night but increasing clouds made me decide to do it much sooner. Mounted the D7200 DSLR at prime focus and did a focus test on the star Shedir using a Spike-a Bahtinov Mask. This is an unguided 30 second, ISO 2500, exposure:
After ending the imaging I began closing up for the night. But it was good to be back in the observatory again!
Close: Thursday, 17 September 2015, 1947 MST
Session Length: 1h 40m|
Conditions: Partly cloudy with distant lightning flashes
On Friday, 11 September, the Friends of Oracle State Park held a social and fundraising event "Dessert in the Desert" at Oracle State Park. One of the raffle drawing prizes was a special visit to Cassiopeia Observatory! Congratulations to the winning family! See you soon at Cassiopeia Observatory!
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