With moisture from what had been Pacific Hurricane Priscilla and an additional tropical storm forecast to bring up to six inches of rain here over the next six days, on Wednesday morning, 8 October 2025, I put the Dome Cover ON. The rain amount forecasts dramatically changed over the next two days, decreasing to 1-3". Rain finally arrived just before sunrise on Saturday, 11 October, and continued sporadically the rest of the day (0.24"). Although some parts of southern Arizona received heavy rain on Sunday, 12 October, only 0.08" fell here. Monday, 13 October, had several occasional brief showers (0.93"). With clear nights now forecast, Tuesday morning, 14 October, I removed the Dome Cover.

Open: Tuesday, 14 October 2025, 1809 MST Temperature: 79°F

Session: 2100 Conditions: Clear, breezy

Equipment:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 30mm eyepiece

Camera:
iPhone 15 Pro Max
D850 DSLR

SYNCed observatory clock to WWV time signals.

1816 MST: LX600 ON, StarLock OFF, High Precision OFF.

1825 MST: Wi-Fi ON.

Using SkySafari 7 Pro on the iPhone, slewed to Comet C/2025 R2 (SWAN). It was not yet visible in the twilight sky.

1833 MST: Comet C/2025 R2 (SWAN), faintly visible, 81X. Coma only, no tail.

1837 MST: Relaxed on the observatory patio bench while waiting for the sky to get darker.

1838 MST: Took this handheld iPhone 15 Pro Max photo of a bright satellite passing near the constellation of Cassiopeia, Camera app (Night Mode, 10 seconds, 1X lens).

1850 MST: Back inside the observatory.

Attached the LiDAR Cover on the iPhone and mounted the iPhone on the 2" 30mm eyepiece.

1858 MST: StarLock ON.

Comet C/2025 R2 (SWAN), iPhone 15 Pro Max, afocal 81X, StarLock autoguided, NightCap Camera app (Long Exposure, Light Boost, ISO 10000, 1sec, 1 minute, 1X lens).

Then viewed the comet, 102X. Bright coma, no tail.

Mounted the D850 DSLR at prime focus, focused on the star Altair, and locked the 12" primary mirror. Slewed back to the comet using SkySafari 7 Pro on the iPhone.

Took this StarLock autoguided image (1 minute, ISO 5000, White Balance 4550K).

1935 MST: Wi-Fi OFF, StarLock OFF.

Viewed Comet C/2025 R2 (SWAN), 12x50 binoculars. Big coma, no tail.

Then viewed Comet SWAN again, 102X. Large, bright coma now visible, but still no tail seen.

Viewed Saturn, 102X.

1950 MST: Back to the bench for some post cataracts surgeries eye tests. I will report on the tests in an upcoming report.

2010 MST: Back in the observatory.

Viewed M31 (Andromeda Galaxy), and its satellite galaxies M32 and M110, 102X. Very nice view.

2016 MST: LX600 OFF.

2023 MST: Took a Sky Quality reading on this night with high humidity and reported the result to Globe at Night.

Close: Tuesday, 14 October 2025, 2029 MST Temperature: 63°F

Session Length: 2h 20m Conditions: Clear, SQM 20.64 (high humidity)

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