This is a bright event, but very short; only 0.2 seconds. I highly recommend you integrate at 1x, and defocus a bit to spread the image over more pixels. Don't lower your gain or gamma. Leave them at max Gain=41, gamma=1.0. The path is well south of Karl, but Bernard is on the northern edge, and Kirk and I are best placed. It misses off shore of Aptos and doesn't enter land again till Monterey.
Alt=39, Az=256 in Cancer, in the west, about 9 degrees below Mars
|
|
Observable for Bernard if a small shift, but not Sandy or Karl
I set up on Llama Ranch Rd, in Cave Gulch near UCSC, 55 ft west of the faint dirt road angling up, and 10 ft east of the power pole. I used 2x setting. There's variable slight aerosol evident in all light curves. Remarkably, the optimum smoothing interval for the metric flatness optimum was a smoothing length of only 4 points. I don't recall ever having so short a smoothing interval. However, my detection of this short event was quite good. The minimum in the figure of merit was rather sharp, and especially sharp if I tried to shift the ref1 curve in either direction from 0. My reference star was the dimmer of the bright double star just to the left of the target by about 1 arcmin. Kirk Bender used this same star for his reference. The duration of my event was 0.24s, about as predicted, and within a second of the (rounded) predicted event time. It looks pretty solid, with a NIE offset in distributions of 6.9 sigma.
I used a 2.4px mask static circular for all stars
magDrop report: percentDrop: 95.8 magDrop: 3.431 +/- 2.928 (0.95 ci)
DNR: 2.30
D time: [04:53:46.5569]
D: 0.6800 containment intervals: {+/- 0.0120} seconds
D: 0.9500 containment intervals: {+/- 0.0368} seconds
D: 0.9973 containment intervals: {+/- 0.0914} seconds
R time: [04:53:46.7969]
R: 0.6800 containment intervals: {+/- 0.0120} seconds
R: 0.9500 containment intervals: {+/- 0.0368} seconds
R: 0.9973 containment intervals: {+/- 0.0914} seconds
Duration (R - D): 0.2400 seconds
Duration: 0.6800 containment intervals: {+/- 0.0188} seconds
Duration: 0.9500 containment intervals: {+/- 0.0458} seconds
Duration: 0.9973 containment intervals: {+/- 0.0934} seconds
 |
 |
 |
 |
 |
 |
 |
 |
Kirk's event agrees with mine in time and duration, but is much noisier. I'm puzzled why, since it was my record which had the wavy light curves. Kirk's are simply wider. Perhaps because he integrated at 1x as I had suggested? Maybe his timings would be better determined if he combined his 1x into 2x in PyOTE? His optimum smoothing is, as he usually finds, almost as long as the total light curve duration. I wonder why I had wavy light curve lines and he did not. Local light cirrus? I didn't notice any visually. Something in the fact I used a small mask of 2.4px? That's usually the best px value if I'm in focus, as I was for this event. Still, I don't see how that would create such waves. The waves were quite coincident for all 3 stars, and the faint target at 2x had no waves after calibration, and a pretty clean 0.240 sec event of high significance.
I tried again with a nest of apertures in PyMovie and found increasing the size from 2.4 to 4.3 gave a more convincing NIE sigma distance of 2.0, from the previous 1.3, also DNR and containment intervals slightly better. Mag drop of 2.447 is still lower than predicted 7.6, however the target was dim and was already close to background.
magDrop report: percentDrop: 89.5 magDrop: 2.447 +/- 2.305 (0.95 ci)
DNR: 1.15
D time: [04:53:46.2761]
D: 0.6800 containment intervals: {+/- 0.0224} seconds
D: 0.9500 containment intervals: {+/- 0.0792} seconds
D: 0.9973 containment intervals: {+/- 0.1845} seconds
R time: [04:53:46.5430]
R: 0.6800 containment intervals: {+/- 0.0224} seconds
R: 0.9500 containment intervals: {+/- 0.0792} seconds
R: 0.9973 containment intervals: {+/- 0.1845} seconds
Duration (R - D): 0.2669 seconds
Duration: 0.6800 containment intervals: {+/- 0.0324} seconds
Duration: 0.9500 containment intervals: {+/- 0.0943} seconds
Duration: 0.9973 containment intervals: {+/- 0.2051} seconds
 |
 |
 |
 |
 |
 |