The Occultation of a 9.6 star by Pafuri

Mar 31, 2022 at 12:32am

 

This is a nice event, high rank, bright, and goes through Santa Cruz and with a northern limit just a bit north of Karl. Worth a try from all 3 of us. Clouds are going to dog us, but we may be OK with such a bright star... My plan is to be on Mill Rd, Karl from home, and Kirk perhaps from the Eco Preserve at BD.

 

   

 

Results:

Karl needed extra time to set up away from his property, and ran out of time. Kirk had trouble escaping the clouds, but still got set up and hurriedly taped and got the event, but because of the clouds, still had the camera on 32x so time resolution suffered. He was on Empire Grade. I set up on Mill St near DeLaveaga Park and Branciforte and also had clouds but they did not cover the target until nearly 2 minutes after the event. I got a very good 2x taping of the occultation and high precision timings.

Nolthenius Results

I had little time to drive long distances to try to not overlap with Kirk. I can't access the western sky from home so had to drive regardless of any weather. There was predicted passing post-storm clouds but the satellite images suggested the clouds were not elevation-dependent, so I decided to just drive close, to Mill St near DeLaveaga Park up Branciforte.

PyMovie screen

PyMovie light curves for the tracking star (blue), sky (green), and the target star (red)

 

The target star drop was complete, as predicted. Note clouds came in about a minute after the event.

The light curve of just the tracking star, which was much dimmer than the target. Clouds again came in at the end.

PyOTE analysis

PyOTE light curve. No comparison star calibration used.

Pretty definite occultation!

Zoomed in.

The timing error bars are so tight they're almost impossible to see.

  

PyOTE log file

Duration 6.32s, S/N=2.73, mag drop 3.9

 

Kirk Bender's Data

Clouds and time constraints resulted in this observation being recorded at 32x integration and very near the chord of Richard Nolthenius' observation of this event.

I used PyOTE's auto-fill function for the timings, after exporting the report form to .xlsx format using Libre Office. 
 
In spite of the clouds and recording at 32x, t​here was a clear event with a deep D and R.  However, this light curve was problematic for PyOTE:  I was late to record, and the event occurred very soon after the start of the recording. In addition, clouds caused the curve to rise after the event. On the first run, I used the entire curve, and PyOTE gave a non-zero false probability with wide timing, over-encompassing the sharp narrow drop.   On a second try, I used the trim function to only use the area near the event, which resulted in a zero false positive and narrow event.
There was an obvious event in my recording, but I would understand if this report needed further review, or even disregarded considering the 32x timing accuracy and being very near to Richard Nolthenius' chord with his much smaller 2x integration.