This is a bright star, dark sky, should be done at 1x. Do-able from Quail Hollow Park, and Canham Rd. I'm tentatively planning on Canham Rd. Also do-able from the top of Rodeo Gulch Rd.
Alt=23, Az= 251 in Virgo
Rank is good, RUWE = 0.90 which is solid. Karl is just barely above the 1-sigma northern limit so his observing from home would be a valuable observation too.
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Karl and I both tried this one. I intended to drive to Canham Rd in north edge of Scotts Valley, but ran short of time and turned off on Santa's Village Rd and set up there, hoping the trees would allow enough of a SW view. Yes, barely. I set up efficiently, got on target efficiently, and got it on 1x OK, for 2 minutes on either side of the predicted moment.
Start 9:51:59 pm
End 9:54:00 pm
Clearly you can see below that I got fooled by the ease that I could see the target on the computer screen (not ease, really, but it was visible anyway), and doing this at 1x was just an over-reach. The data show the target light curve is full of dips to zero. No conclusion possible. Karl said he was surprised I could see it at 1x. He needed 4x to see it well enough. This is not what I'd have expected for an 11.7 mag star. I'd have thought 1x was good, and 2x completely good for a star of that magnitude. Maybe it was much hazier than expected. My site was looking over Hwy 17 and Scotts Valley, with the star low in the SW. Bright sky.
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Too many dips to zero. A short event can't be ruled out or even detected. |
PyOTE could not find a detectable event above noise. Or rather, I had to try trimming and trimming and it kept finding better prospects than the one that is the most likely to be real, and yet the ones it found totally failed the NIE test with negative sigmas. The duration was long enough it should have been visible. But I can't rule out a rather shorter event than 0.1s. I'll call it a "miss" and "unsure".
Observed from home. Single-stepped through frames and thinks he had a miss. But, at 4x, that's 4/64 sec per integration or 1/16 or .066s integration. That's enough for 2-3 points inside the occultation so that should be enough, if he had a positive. If there was a significant dip if not to zero, it may still be a short positive. I will have to examine my own tape to say more...
