This event is nominally of high rank, central through Santa Cruz. But RUWE is a little high at 1.35. Still probably good through Santa Cruz. The eyepiece chart is about 1/2 of a field away from NGC 6645 Open cluster m=8.5. The whole area is a dense star field. And the target is only 8" away from a star 0.2 magnitudes dimmer. This will mean the drop may be only 0.8 magnitude and not the advertised 2.5 magnitude for the combined image, but the combined image will be 0.6 magnitude brighter than said, or about 13.3 This could make it easier. Duration is only 1.7s though.
Karl is in the path too. It's tough. W=13.3 with only half the drop nominally given, so will require good signal and so a high integration, like maybe half a second =32x. Alt=24, Az=224 in the SW in Sagittarius. Very dim, and challenging. But skies look crystal clean. But, we have a full moon too, in opposite part of sky. Not sure what I'll see, but we shall see what we see...
I am planning on trying to build a mount model for the 12" at Cabrillo and planning on trying this event from Cabrillo Observatory, taking a break from the 12" work. (But, decided to wait till Tuesday for that job. I did not observe from Cabrillo).
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I ended up observing from the west side of the bike trail at the Upper Meadow UCSC, under clear skies, with the full moon and Jupiter rising in the East. The recording went fine, but the event was just too difficult in the bright sky. I integrated at 16x. 32x was just too bright. I saw a dip at the right time on the light curve, but it came nowhere near meeting the false positive test. The point to point scatter was just too large to see a 0.8 mag drop. The target looked dimmer than the advertised 13.3 magnitude.
The target is shown; it's a blend of the star+asteroid + neighbor star and looks fuzzier than the other stars for this reason. |
Target+neighbor in gold |
No clear occultation, but the signal is too noisy to be sure. |
Ran the data through PyOTE and vertical bar shows predicted event time. |
I placed a D and R range on the most likely part of the light curve for them to be. But they failed the False Positive test completely. They were very typical of the normal scatter in the light curve |
When asked, PyOTE did find an event subject to my D and R range, but it was insignificant, reality is unknown. |
No report filed with IOTA.
Observed from "the Berm" up Empire Grade. Very similar results. Just too dim to get a signal.
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Kirk ran a doze different apertures to find the best one. But none gave a detectable signal. |
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Kirk ran the detectability check - says no event of this duration and depth will meet the false positive test in this data. |
Karl tried to set up, but the target was not visible from his front yard due to a big fir tree. No observations.
