The Occultation of a W=13.5 Star by Asteroid 1999JL22

Aug 4, 2024 at 9:40:06pm

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This is a narrow path, short event passing through Santa Cruz. Best place to try this is my place, on the centerline. Fog may wait till after the event, we hope. It's tough. ONly 0.4s long and only W=13.5 at 28 deg altitude, Az=163. Might have to go 8x and hope I get a central event that shows on 4 data points, to get significance.

     

 

Results:

I set up at Llama Ranch Ln in Cave Gulch. Good skies good tracking. But the star magnitudes on the C2A chart were way off. The star next to the target was MUCH brighter than shown, making isolation of the target tough. I used 11 px boxes and 2 px radius for the target star. The neighbor star was so close it's light polluted the aperture box and made the target look to be ~zero. However, it's light curve shows above zero fairly well. There's a single 8x integration below zero at the predicted event, but that's not enough for PyOTE to find it, as there are many others. Not a convincing miss, not a convincing occultation. It's a "unknown". A full 0.4s event might at least show well enough to find the event, even if not at the 5-sigma level, but PyOTE can at least say that if there were an event it was shorter than 0.4s max

No one else tried this one. No IOTA report to be submitted.