This is a bright and long occultation visible for the entire team from their homes.
Alt=31, Az=257, due left 10 degrees of Denebola in western Virgo in the west.
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There's strong evidence this was a binary star, not noted as such on the C2A data sheet. It's clearest in my recording, but also shows on Kirk's record for the D, not so clear on the R. Karl's recording is not zoomed properly to see clearly, but it looks like steps in the the D and R in Karl's recording.
I got a long occultation, from the Ocean St extension SE of the entrance to the mausaleum of the Santa Cruz Memorial Park. At 1x. I see good evidence this was a binary star. The tracking star, unfortunately, was the only star available for tracking, (or reference) and it had a half dozen saturated pixels at many times during the recording. Still, I don't see obvous clipping on the bright side of the noise distribution, so I don't think it's serious. I also don't see any evidence of significant aerosols variations as seems rather common in our light curves. The skies looked unusually clean for Kirk and I. Since there's no real evidence of significant cloud or aerosol. I used the ref star and tracking star as the bright nearby star, and a long smoothing length did help the target flatness. I see distinct steps in the D and the R for my data. The companion star looks roughly about 1/3 the brightness of the total combined light; i.e. two roughly equal brightness stars very close together, in tight orbit. Unless we're looking pole-on to the orbit, it should show evidence of being a spectroscopic binary by the Doppler Effect. I don't know if that has been searched for in whatever Doppler data is out there.
long=122 01 41.12, lat=36 59 25.12, elev=22m. 85 ft South of the center of the "y" shaped entrance to the Santa Cruz Mausaleum, on the west side of the road in the dirt.
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I've reduced this as a binary star separately, see below. The D looks to be more complex than shown above and will be reported as D1, R1, D2, R2, R3 |
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I'm switching to a separate folder and webpage for the binary star analysis results.... Binary Star Timings Extraction
I got a 6.6 second event for Emita on June 16, 1x from home. There were no missing timestamps like Gaussia, which I also did at 1x. There was only one other star to use for tracking and reference. It was bright but I had the gain reduced while recording so it was only occasionally saturated with one red pixel in PyMovie. Since it was so much brighter I've included some plots to zoom in without it.
RN: The reduction below does not account for the evidence of it being a binary, treating the entire light curve with a single square wave assumption. So, these timings are not the last word in these reductions. There's clear evidence for a stepwise D, not so much for the R, which may have stepped too rapidly for a clear enough step.
magDrop report: percentDrop: 96.6 magDrop: 3.656 +/- 0.428 (0.95 ci)
DNR: 2.74
D time: [06:17:22.6402]
D: 0.6800 containment intervals: {+/- 0.0049} seconds
D: 0.9500 containment intervals: {+/- 0.0138} seconds
D: 0.9973 containment intervals: {+/- 0.0412} seconds
R time: [06:17:29.2467]
R: 0.6800 containment intervals: {+/- 0.0049} seconds
R: 0.9500 containment intervals: {+/- 0.0138} seconds
R: 0.9973 containment intervals: {+/- 0.0412} seconds
Duration (R - D): 6.6065 seconds
Duration: 0.6800 containment intervals: {+/- 0.0071} seconds
Duration: 0.9500 containment intervals: {+/- 0.0174} seconds
Duration: 0.9973 containment intervals: {+/- 0.0474} seconds
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RN: This reduction of Emita should be re-done, with special care on the D and R areas to ascertain duplicity of the star. But the first pass through by Karl shows the following timings...
Duration: 0.9973 containment intervals: {+/- 0.0762} seconds
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The occultation managed to happen before the bright tracking star drifted into the bright numerals of the VTI, ruining tracking. |
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There's good evidence for a Stepwise D. Not so for the R. Were the two components aligned with the perpendicular to the path and parallel to the local surface of the asteroid at the R? |
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