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ETX-90AT observing & iPhone Moon Imaging

Posted: 28 March 2021

Cloudy skies and wind returned on Tuesday, 23 March 2021. Rain began in the late afternoon (0.07"). Clouds, wind, and occasional drizzle continued on Wednesday, 24 March. Thursday, 25 March, was cloudy and windy. Friday, 26 March, was clear and windy during the daytime; the wind died down as sunset approached but the sky became overcast. Saturday, 27 March, dawned clear and mostly calm. Saturday afternoon I was at Oracle State Park to do some video recordings for the Virtual Star Party to be held on 10 April 2021. Some clouds appeared as sunset approached.

Open: Saturday, 27 March 2021, 1824 MST
Temperature: 74°F
Session: 1615
Conditions: Partly cloudy

f/13.8 ETX-90AT
1.25" 26mm eyepiece
1.25" 9.7mm eyepiece
1.25" 5.5mm eyepiece

iPhone 11 Pro Max

I set up my Meade ETX-90AT on the observatory patio.


1830 MST: nearly full Moon rose over the hill to the east.


1839 MST: ETX-90AT ON.

Did a fake AutoStar star alignment.

1843 MST: sunset.

Viewed the Moon, 48X, through tree branches. A very slight terminator was visible.

1900 MST: I moved the ETX-90 telescope to a better location to try for Nova V1405 Cas, which was low in the northwestern sky. I then did a real Autostar star alignment.

Viewed the Moon, 48X, which was now out of the tree branches.

Took this handheld iPhone 11 Pro Max afocal 48X photo of the Moon using NightCap Camera (ISO 32, 1/500sec, 1X lens).


1910 MST: did a GOTO M52 (open star cluster). Nova V1405 Cas is very near the cluster and would be in the same eyepiece field-of-view. Unfortunately, M52 was too low and behind a tree.

Viewed M42 (Orion Nebula), 48X. Some nebulosity was visible against the bright moonlit and twilight sky. The Trapezium star cluster looked nice.

1925 MST: viewed the planet Mars, 48X. The disk was visible but very small. No surface features were visible. Then viewed Mars, 129X. Still no surface features visible. Viewed Mars, 227X. Still small disk without any surface features visible.

Viewed the Moon, 129X and 227X. The view of the terminator at 227X was good.

Took this handheld iPhone 11 Pro Max afocal 227X photo of the lunar terminator using NightCap Camera (ISO 500, 1/60sec, 1X lens).


Took a final look at the Moon with the ETX-90, 48X.

1941 MST: ETX-90AT OFF.

Close: Saturday, 27 March 2021, 1951 MST
Temperature: 57°F
Session Length: 1h 27m
Conditions: Clear

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