The Occultation of a W=11.6 Star by (50653) 2000 EV92

May 5, 2025 Mon eve at 10:27:57pm

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This is a bright event which skims the Santa Cruz coast. Can't get to the centerline w/o a drive to south of Watsonville. The centerline just touches Natural Bridges, which is where I have decided to set up. Weather is supposed to be fog-free this night. The path misses Karl entirely, and Bernard, and Sandy.

Max duration is predicted to be only 0.4s, and is only 19 degrees from the gibbous moon.

Alt=41, Az=247 in Cancer, in the WSW

     

 

Results:

Richard Nolthenius

Clear skies, but with heavy humidity at Natural Bridges where I observed. I set up right at the closed entrance gate on West Cliff where it enters Natural Bridges State Park, just before it descends to the parking lot. A hint of fog forming but it was clear during the event. I recorded it at 1x, with target quite faint on the monitor but the sky quite dark too. I think it'll reduce OK.

PyOTE indeed finds an event at the predicted time, of duration only 0.144 seconds, but looking decently likely to be real. 3 or 4 consecutive points all lie pretty close to zero, and no other place on the light curve shows that long a duration, although there are up to a dozen single points near zero and two places that had two consecutive points near zero. The NIE distributions are 3.4 sigma apart, which is unlikely to be due to chance (actually, less than 0.21% chance of being random noise.

magDrop report: percentDrop: 92.2 magDrop: 2.776 +/- 1.981 (0.95 ci)

DNR: 2.26

D time: [05:27:56.5301]
D: 0.6800 containment intervals: {+/- 0.0123} seconds
D: 0.9500 containment intervals: {+/- 0.0372} seconds
D: 0.9973 containment intervals: {+/- 0.0886} seconds

R time: [05:27:56.6737]
R: 0.6800 containment intervals: {+/- 0.0123} seconds
R: 0.9500 containment intervals: {+/- 0.0372} seconds
R: 0.9973 containment intervals: {+/- 0.0886} seconds

Duration (R - D): 0.1436 seconds
Duration: 0.6800 containment intervals: {+/- 0.0186} seconds
Duration: 0.9500 containment intervals: {+/- 0.0457} seconds
Duration: 0.9973 containment intervals: {+/- 0.0912} seconds


   

Kirk Bender

Observed from home, tried to do it with the new Astrid, but ran out of time with various learn-by-doing issues. Fumble! Better to record on the well-practiced Watec, and then swap in the Astrid and record and compare the depth of the recordings