This is a star of V mag 13.4 but B mag 16.5 and so the W magnitude translates to 12.6. Sometimes the brightness is not so easy visually as suggested. We'll need it to be good, since the event is only 0.4s long.
Alt=43, Az=203 in Serpens near Globular Cluster IC 1276 (mag 10.3)
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I got a recording on camcorder only, from outside room 806 on campus. Could barely see the star occassionally on the flakey flip out screen. Brightness and contrast both just set in the middle of the range. Sky brightness on screen looked bad. Not reduced yet. Good conditions otherwise; moon not on screen, clear skies but a low marine layer that was still transparent but seemed to hold some schmutz anyway.
The target was much fainter than the Plavec formulat for W suggested, in a still slightly twilight sky. However, the star was detected on the large majority of integrations, and there is a deep drop precisely at the predicted time of 2:58:32.7. The drop was extended, however and PyOTE found an unreasonably long event of 1.76s. However, the error bars allow a much shorter event within limits. So, likely the event was much shorter, at 0.4s or so, if that. I had to trim most of the light curve away to get a detection in PyOTE, at 2.8 sigma NIE. Through a confusion in dealing with a dozen students around the telescope during this event, the recording was terminated only 10s or so after the event, but there was a 3 minute recording before the event (when twilight was worse, alas). The star was more reliably visible during the live recording during the final minute which was when the event occured. The nominal path had me on the northern limit, at likely decent rank. I would normally have indicated the S/N was insufficient to judge an event. However, since Kirk Bender across town got a decent detection from the centerline, I thought it best to report what this recording gives, and let the reviewers decide its fate.
I'll file this as a "positive" "unsure" on the IOTA form.
magDrop report: percentDrop: 40.2 magDrop: 0.559 +/- 0.206 (0.95 ci)
DNR: 1.54
D time: [02:58:32.7374]
D: 0.6800 containment intervals: {+/- 0.1703} seconds
D: 0.9500 containment intervals: {+/- 1.0420} seconds
D: 0.9973 containment intervals: {+/- 2.3527} seconds
R time: [02:58:34.4974]
R: 0.6800 containment intervals: {+/- 0.1703} seconds
R: 0.9500 containment intervals: {+/- 1.0420} seconds
R: 0.9973 containment intervals: {+/- 2.3527} seconds
Duration (R - D): 1.7600 seconds
Duration: 0.6800 containment intervals: {+/- 0.3761} seconds
Duration: 0.9500 containment intervals: {+/- 1.2499} seconds
Duration: 0.9973 containment intervals: {+/- 2.8315} seconds
I used horizontal and vertical median filtering, static circular 2.4px masks as best. |
The recorded ended only 11s after the event, unfortunately. But plenty of integrations ahead of the event, but in stronger twilight. |
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I had to heavily trim the light curve to get a PyOTE detection with any significance. |
The 2-sigma error bars allow a very short occultation which would be much more in line with the prediction. The deepest point was at the predicted event moment. |
The solution w/o using a reference star actually gave a stronger detection. NIE=3.6 sigma |
The timings quoted above are using ref1 as a reference star. The D and R intervals were set, giving the timings detected |
Surprisingly, I got an event for Hollycheng, 8x from home on Sep. 28. I could barely see the target in the monitor and the sky was washed out from twilight and light pollution, but pyote found an event near predicted time, I got the best results in pymovie with a size 4.3 mask. The duration of 1.2s is longer than the predicted 0.39s, but I guess it's possible within the containment intervals. The mag drop is lower than predicted, but the target was so dim and the curve meshed with no-star level that it didn't have far to drop.
NIE sigma distance = 2.7.
magDrop report: percentDrop: 78.1 magDrop: 1.648 +/- 0.687 (0.95 ci)
DNR: 1.32
D time: [02:58:31.7765]
D: 0.6800 containment intervals: {+/- 0.0767} seconds
D: 0.9500 containment intervals: {+/- 0.3073} seconds
D: 0.9973 containment intervals: {+/- 0.7396} seconds
R time: [02:58:32.9777]
R: 0.6800 containment intervals: {+/- 0.0767} seconds
R: 0.9500 containment intervals: {+/- 0.3073} seconds
R: 0.9973 containment intervals: {+/- 0.7396} seconds
Duration (R - D): 1.2012 seconds
Duration: 0.6800 containment intervals: {+/- 0.1305} seconds
Duration: 0.9500 containment intervals: {+/- 0.3642} seconds
Duration: 0.9973 containment intervals: {+/- 0.7602} seconds
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