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Daytime Occultation of Venus

Posted: 12 December 2020

Monday, 7 December 2020, was cloudy, a day earlier than was forecast. Cloudy skies continued until Wednesday, 9 December, which dawned clear, but clouds returned mid-afternoon. Thursday, 10 December, had several brief periods of light rain (total 0.34"). Friday, 11 December, dawned clear, but clouds returned mid-morning, increasing sky coverage as sunset approached.

Saturday, 12 December, was mostly cloudy with thin clouds and was windy. I planned to try to image an occultation of Venus by the crescent Moon in mid-afternoon. They would be low in the southwestern sky.

Open: Saturday, 12 December 2020, 1331 MST
Temperature: 71°F
Session: 1568
Conditions: Mostly cloudy, thin clouds, windy

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
Focal Reducer


SYNCed the observatory clock to WWV time signals.

1337 MST: LX600 ON, StarLock OFF, High Precision OFF.

Attached the Astrozap Dew Shield to increase contrast through the 12" telescope.

1343 MST: viewed Venus, 102X.

Mounted the D850 DSLR at prime focus + focal reducer. This is the setup.


I was now ready for the occultation of Venus to begin. Disappearance would be at 1431 MST, with reappearance at 1536 MST. They would be too low for imaging from Cassiopeia Observatory at reappearance.

1359 MST: the thin crescent Moon was faintly visible in the camera viewfinder.

I took this series of images (slightly cropped) as the Moon approached Venus (1/1600sec, ISO 100).

1405 MST

1414 MST

1426 MST

As the time of the occultation got closer the clouds began getting thicker, as seen in the last image above.

By the time the occultation began the Moon was nearly invisible. I did a 1080p, 60 fps, video recording at 1/1600sec, ISO 100. Click the image below to view the 38 second video.

Click or tap on image to view video

Strong wind gusts can be heard in the video, resulting in some shaking of the telescope. Clouds going by are also visible.

1437 MST: LX600 OFF.

Close: Saturday, 12 December 2020, 1447 MST
Temperature: 63°F
Session Length: 1h 16m
Conditions: Mostly cloudy, thin clouds, windy

I am honored to have been selected by Indiana University College of Arts & Sciences for its "Alumni Spotlights".


Read the article at Celebrating Alumni Contributions: 200+ Years of Impact.

I have posted my review of the Pixel Wireless Shutter Release.

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