This is a high rank event with wide path going centrally through the Santa Cruz Mtns. The northern limit area includes our two SiValley colleagues, and both Santa Cruz and Karl are well inside the limits. Should be a well observed event. Weather predictions are very good. We should have a good astrometry measurement for this asteroid. Alt=30, Az=91. Karl might need to go to the bend just above his place for a good view, or maybe not. It's due east at 30 degrees altitude. The sun is at -21 so there should be plenty of time to align and get on target in a dark sky, given low enough horizon line. I will plan to observe from Cabrillo Observatory most likely, where I hope to do some work this afternoon. If not, from perhaps a little closer to the limit on the drive home, to get a little separation from Kirk's home where I suspect he'll try to observe it. However, east is not a good direction for his place and he might want to observe from elsewhere.
The target is in Orion's club, above/left of Betelgeuse and midway between Gemini's feets.
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Kirk and I both got 4s events. Karl had horizon problems. No data. Kirk's data and mine, and two more observers are on the sky plane solution on the IOTA site
I observed from the base of my stairs at home. Got a good recording of a ~3 second event. 4x setting. Probably could have done 2x easily. The PyMovie light curve shows classic Fresnel diffraction spikes at the D and R. I tried to do a Fresnel analysis in PyOTE, but the stellar diameter field was not given in OWc for this star, which appears rather bluer than most in V-R, bluer than the sun. Without the stellar diameter doing the fresnel method doesn't seem to give me a go-ahead for finding the D and R; it won't let me mark D region and R region. So, I did a standard square wave analysis instead.
Also in PyOTE there's a "cadence error" a few seconds after the occultation. But I look at the time stamps read and shown in the CSV file, and they look normal and correct surrounding that cadence error, so I don't know why Pyote was unhappy. In any case, it was outside the occultation period and I got a good solution with extremely high accuracies and strongly passing the FP test.
magDrop report: percentDrop: 88.2 magDrop: 2.323 +/- 0.168 (0.95 ci)
DNR: 6.19
D time: [02:53:03.9011]
D: 0.6800 containment intervals: {+/- 0.0102} seconds
D: 0.9500 containment intervals: {+/- 0.0236} seconds
D: 0.9973 containment intervals: {+/- 0.0471} seconds
R time: [02:53:08.4658]
R: 0.6800 containment intervals: {+/- 0.0102} seconds
R: 0.9500 containment intervals: {+/- 0.0236} seconds
R: 0.9973 containment intervals: {+/- 0.0471} seconds
Duration (R - D): 4.5647 seconds
Duration: 0.6800 containment intervals: {+/- 0.0148} seconds
Duration: 0.9500 containment intervals: {+/- 0.0323} seconds
Duration: 0.9973 containment intervals: {+/- 0.0576} seconds
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Observed from the upper meadow UCSC bike path. Got a ~4s event.
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Target line of sight got into a tree, no time to recover. No data.
