On the night of Sep 12/13, 2023, under poor conditions, I was unable to measure an occultation by (704) Interamnia because clouds covered the field at the time of the event. On the bright side, I was able to set up the equipment properly, and the camera did acquire images of the field before the clouds arrived.
The event was an occultation of TYC 2413-01480-1 by (704) Interamnia. The shadow path crossed a large section of the United States, so IOTA designated this event as one of their official campaigns for the year. The star as bright, at V = 9.1, and the dip in brightness was large -- a drop of about 2 magnitudes, so it was a good choice: easy to observe.
I set up the equipment starting very early and was on the field by about 4:30 AM, more than 90 minutes before the occultation. In order to focus the telescope with this camera (instead of the usual ASI cooled camera), I had to turn the silver focus knob about 4-6 small turns CCW. After that, I was able to bring starlight to a focus at a position of 1.095.
I acquired images with 54-ms exposure time, at 60-ms intervals, which did clearly show the field. Here's a chart from the Digitized Sky Survey, about 0.5 degrees on a side ...
... and here's a median of 50 images from one of my sequences this morning:
The skies were reasonably clear around 5:00 AM, but by 5:15 AM, clouds returned. They remained thick for over an hour, and well past the 6:17 AM time of the occultation. I wasn't able to see anything. Rats.
So, I put all the equipment away and closed the dome. As I walked to the car, around 7:00 AM, the eastern half of the sky -- the location of the field -- was perfectly clear.
Argh.
I reported "clouded out" to the IOTA server and called it a night. Fortunately, a number of other observers were able to detect the occultation.