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DSLR Venus, Saturn; iPhone Summer Triangle

Posted: 23 August 2021

Open: Sunday, 22 August 2021, 1826 MST
Temperature: 84°F
Session: 1656
Conditions: Clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 4X Powermate
2" 2X Powermate

iPhone 11 Pro Max

1830 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Venus, 102X, 406X, and 812X. Nice views of the gibbous phase.

Mounted the D850 DSLR at prime focus + 2" 4X Powermate + 2" 2X Powermate. Took several photos of Venus (1/400sec, ISO 1600). This is a stack of 5 images (cropped).


1852 MST: began relaxing on the observatory patio bench.

1901 MST: sunset.

Had this grasshopper visit the observatory.


On the previous session I mentioned timing how soon at the Sun sets I could see the "Summer Triangle". I had determined that Vega appeared 12 minutes after sunset, Altair 17 minutes, and Deneb 18 minutes. If you want to try this experiment, here is an iPhone 11 Pro Max photo using the Camera app (Night Mode, 3 seconds, 1X lens) to help you identify the stars. The image was taken this night 35 minutes after sunset. Face towards the east and look high up in the sky.

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1950 MST: the eastern sky was lighting up from lightning in a storm 55 miles to the east.

1957 MST: the eastern sky was brightening from the rising just past Full Moon.

1959 MST: iPhone photo (Night Mode, 3 seconds, 1X) of the Summer Triangle and the constellations of Lyra (top), Cygnus (left), and Aquila (lower right).


2004 MST: took this iPhone photo (Night Mode, 10 seconds, 1X) of a satellite passing by Cygnus.


2030 MST: back inside the observatory. Viewed Saturn, 102X, 406X, and 812X. Some clouds were appearing in the southeastern sky.

Mounted the D850 DSLR at prime focus + 2" 4X Powermate + 2" 2X Powermate. Took several photos of Saturn. Seeing was not very good and stacking images did not yield any good images. This is a single full-frame image of Saturn, 1/10sec, ISO 3200.


Viewed Jupiter, 102X, 406X, and 812X. The four Galilean Moons were in the same field-of-view at 812X.

2055 MST: viewed the Moon, 102X, through a tree. A slight terminator was visible.

2106 MST: LX600 OFF.

Close: Sunday, 22 August 2021, 2115 MST
Temperature: 75°F
Session Length: 2h 49m
Conditions: Mostly clear

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