Cassiopeia Observatory logo

Summer Triangle

Posted: 28 September 2019

Saturday morning, 21 September 2019, I had a nice friendly visit with this rattlesnake:

Click or tap on image for larger version

Later that afternoon I gave a talk at Oracle State Park (our local IDA "International Dark Sky Park") on the potential for Oracle to become an IDA "International Dark Sky Community". There was a star party at the Park following my talk. My report has been posted.

Clouds began arriving mid-day on Sunday, 22 September, from the approach of the remnants of Pacific Hurricane Lorena. Following that storm system were the remnants of Pacific Hurricane Mario. Monday morning, 23 September, was an active storm day in parts of Arizona, just not here. A portion of Phoenix (about 2 hours north of Oracle) received 3" rain and had a tornado. There was another Arizona tornado Monday evening near Willcox (east of Tucson). Finally got some rain (0.28") on Tuesday, 24 September. The second round of storms arrived on Wednesday, 25 September, and dropped 0.11" rain here.

The sky dawned mostly clear on Thursday, 26 September, but clouds began appearing mid-morning, becoming mostly cloudy mid-afternoon. This is a Tornado Warned storm that was in Pima County late in the afternoon, but there was no tornado:


Had another 0.53" rain over night through Friday morning, 27 September. The sky began clearing late afternoon.

Open: Friday, 27 September 2019, 1811 MST
Temperature: 84°F
Session: 1385
Conditions: Mostly clear, high humidity

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


1816 MST: sunset.

SYNCed observatory clock to WWV time signals.

1819 MST: LX600 ON, StarLock OFF, High Precision OFF.

1822 MST: viewed the planet Venus, low in the western sky, 102X. Chromatic dispersion was very evident. As Venus was about to go behind a tree I did not add the Atmospheric Dispersion Corrector.

1833 MST: Meade Stella Wi-Fi Adapter ON.

Used SkySafari 6 Pro on the iPhone 8 Plus to GOTO the planet Mercury, low in the western sky. Not a very good view as it was getting behind a tree, 102X.

I then did some tests of the iOS app ScopeBoss for the developer. I had just updated the iPhone to iOS 13.1 and wanted to verify that ScopeBoss still worked as expected. It did. Reported that information to the developer.

1837 MST: viewed the planet Jupiter, 102X. Two moons were visible.

1848 MST: viewed the planet Saturn, 102X. Four moons were visible.

With the high humidity my logbook paper was getting damp.

1903 MST: The Summer Triangle was directly overhead. Although Astronomical Twilight would not end until 1935 MST, the sky was pretty dark so I took this handheld D850 DSLR photo (f/2.8, 1/2sec, ISO 3200, White Balance Auto, Focal Length 24mm) with North at the left and East at the bottom:

Mouseover or tap on image
Mouseover or tap on image for labels

1915 MST: did some sky observing using the Vortex 12x50 binoculars. Toured along the Milky Way. Also viewed the Double Cluster (open star clusters) and the Andromeda Galaxy (M31), both of which were nice views in the 12x50 binoculars.

Decided to close up due to the high humidity.

1920 MST: LX600 OFF.

Close: Friday, 27 September 2019, 1932 MST
Temperature: 70°F
Session Length: 1h 21m
Conditions: Mostly clear, high humidity

Comments are welcome using Email. Twitter users can use the button below to tweet this report to their followers. Thanks.

Previous report

Cassiopeia Observatory Home Page

Back to Top

Copyright ©2019 Michael L. Weasner /