Hi all

Just back, here is a short report on our observing trip to southern Italy, lead by the organization of Astrocampania.

In Calabria near Corigliano (CS) we were able to observe a successful occultation of Betelgeuse. We were positioned at a hotel near chord #29, about 6 km south of the central line in the middle of a mandarin orchard. The weather was good and, apart from a few occasional medium-high clouds, fairly clear. The occasional gusty wind was a bit of a nuisance. It was therefore a good thing that we had set up in a dark corner of the hotel complex, surrounded by a few buildings and trees, so that we were practically unaffected by the wind and only heard the sudden gusts.

I had observed with a Borg Apo refractor with 125mm aperture on a ZWO AM5 mount, which piggybacked another finder telescope, namely a Baader 60mm VARIO Finder with 250mm focal length and a makeshift mounted 50mm Nikon lens. All three instruments had a DVTI cam with integrated GPS time inserter connected and were operated via three different laptops. Photometric R, I and V filters from the Baader Bessel series were used (in this order for the descending aperture of the instruments).

In addition, a video of the entire scene, including us, the equipment and the complete constellation of Orion, was recorded on a tripod set up a little further away. The passage of a band of clouds south of Betelgeuse is clearly visible in the two-minute recording. The camera used here was a very sensitive Sony alpha 7s I DSLR with a 14 mm f/2.8 wide-angle lens. This video was actually recorded mainly to capture the atmosphere during the event. Nevertheless, the darkening of Betelgeuse is also clearly visible here. Under certain circumstances, this video could therefore also be analyzed, as the synchronous flashing of the precise 1PPS LEDs of our DVTI cams can be clearly seen on it and thus the time of the individual frames can be reconstructed quite precisely, if this should be necessary.

Visually, I had the impression that Betelgeuse did lose a noticeable amount of brightness, but this was not as sudden as usual, but rather slow. The drop in brightness was also much less than originally expected. I had a little more trouble when it rose again and would not have been able to clearly determine the exact end time visually. The red giant star "flickered" quite strongly due to scintillation despite its relatively high altitude of 50 degrees above the horizon, which perhaps intensified this effect. Nevertheless, the event was also visually quite impressive.

Below are a few impressions and images including the light curve from the recording of the Borg refractor with the Red filter. At a frame rate of 100 fps, 8000 data points were collected here. The data will soon be uploaded to the Occultation Portal and SODIS.

Best regards,
Stefan Meister
(DVTI Cam Team)