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Weather Updates, More Wildfires,
Cloud Shortened Session

Posted: 1 September 2020

Sunday, 23 August 2020, was cloudy and still very hazy. The Westridge Fire in the Tortolita Mountains (about 20 miles from Cassiopeia Observatory) was 100% contained after burning 480 acres since it started on Monday, 17 August. Had a brief rainshower (0.05") Sunday night.

Tuesday morning, 25 August, I went to the observatory to check on the air conditioner. As expected with the new electrical wiring, even during our current extended period of extreme heat in southern Arizona, the air conditioner is keeping the inside of the observatory 30° cooler. When I arrived at the observatory I saw this tarantula, which was unfortunately dead.


Thursday afternoon, 27 August, a new lightning-caused wildfire broke out in the Tortolita Mountains. The Edwin Fire was in nearly the same location as the Westridge Fire that broke out last week. The smoke is hard to see (center) in the daytime photo due to the thick haze from smoke from fires in California and Colorado.


Sometime later that evening the lightning-caused Dove Fire broke out in the Tortolita Mountains. The night photo shows the Dove Fire (left) and Edwin Fire (right) very clearly as seen from Oracle.

Click or tap on image for larger version

Friday, 28 August, started clear but hazy until mid-day when clouds began appearing. The wildfires in the Tortolita Mountains continued to burn. The Dove Fire had burned 600 acres and was close to merging with the Edwin Fire (137 acres). This photo taken about 50 minutes before sunset shows the smoke plumes.


No flames were visible Friday night. Saturday, 29 August, was cloudy. The Dove Fire had increased to 942 acres, but was 45% contained. The Edwin Fire was 80% contained. Beginning late Saturday afternoon there were some brief thundershowers that continued into the night (total rain 0.15"). Sunday night, 30 August, had another brief shower (0.05") from our so far "nonsoon" Monsoon.

The cloudy and very hazy (smoke from CA and CO wildfires) sky continued to reign over Cassiopeia Observatory until Monday morning, 31 August. The sky was blue with visibility 65 miles once again. However, cumulus clouds began appearing mid-day, but were pretty much gone as sunset approached. The two fires in the Tortolita Mountains were now 100% contained.

Open: Monday, 31 August 2020, 1809 MST
Temperature: 83°F
Session: 1510
Conditions: Mostly clear, breezy

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 5.5mm 100° eyepiece

iPhone 11 Pro Max

SYNCed observatory clock to WWV time signals.

Relaxed on observatory patio bench.

1849 MST: sunset.


1852 MST: LX600 ON, StarLock OFF, High Precision OFF.

1853 MST: viewed Jupiter and the four Galilean Moons, 102X. Then returned to the bench.

1904 MST: spotted Jupiter, naked eye.

1910 MST: the clouds in the west were approaching. Returned to the observatory.

1914 MST: viewed Saturn and two moons, 102X. Seeing was not good (clouds). Viewed Jupiter, 44X. The Great Red Spot was visible. The views of both planets at 443X were barely tolerable at times due to poor seeing.

Mounted the iPhone 11 Pro Max on the 2" 5.5mm eyepiece using the Levenhuk adapter. Took slo-mo (240fps, 10 seconds, 1X) videos using the iOS Camera app. Stacked the videos with these not so great results.

Jupiter, 2486 frames

Saturn, 2507 frames

1930 MST: Clouds were now obscuring the planets with a mostly cloudy sky. Still breezy. Decided to close.

1933 MST: the nearly Full Moon was rising over the hill to the southeast.

1939 MST: LX600 OFF.

1948 MST: took this handheld D850 DSLR photo of the Moon in the clouds (f/5.6, 1/500sec, ISO 400, FL 300mm, slightly cropped).


Close: Monday, 31 August 2020, 1949 MST
Temperature: 77°F
Session Length: 1h 40m
Conditions: Mostly cloudy, breezy

I have posted a completely revised "How I Do Astrophotography" article.

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