The Occultation of a 14.0 star by Brangane

Sept 16, 2022

 

This event was only at 17 degrees altitude, which means even under good skies the effective magnitude is dropped by 0.95 magnitudes, so a 14.0 star will look like a 15.0 star at high altitude, and that's pretty dicey. Worse, this target star is right next to another star of equal magnitude in the dense bulge of the Milky Way, so the drop would not be 1.3 magnitudes as shown on the predictions, but only 0.6, yet on a few perhaps 13.4 total brightness target (looking like 14.4 with the low altitude, though). So, we'd be looking for a 14.4 to drop to 15.0 for at most 2.9 seconds. Yet, we're near the limit, so in fact the occultation would only probably last 1 second or less. Too hard.

Kirk gave it a try, though, from his driveway. He's been remarkably successful with his by-chance very good Watec camera. However, it indeed proved too tough. Here's his light curve from PyMovie, with vertical bar around the predicted event time. I would call it a "likely miss", but not significant enough to report as a miss.

Below is the PyOTE light curve. No drop hinted, and fails detectability (although "detectability" may mean less than 1 chance in 50,000 to be a false positive, which as I continue to hold, is a far too severe criterion.