So Steve told his tale of success and woe with (270) Anahita (interesting observing story). I tried for that event but clouds said otherwise. But the next night I had another 10th mag "possibility".... This involved the 6-digit, 6km rock (248227) - with a moderately wide 1-sigma, but at a nice combined mag of 10.7. [This I found on my own Occult4 search - it wasn't listed on my OW Desktop].
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From my Home observatory Occult4 said I had a 44% chance. At the centerline it rose to 59% - not great, but not bad either. As mentioned, the 1-sigma margins were nearly as wide as the path itself. I examined the path on Google Earth (see attached) and my Home observatory was clearly outside the predicted path. But the thought was to setup my QHY174M-GPS in my Home observatory (for the heck of it...) and use the Sequencer function in SharpCap to automate a recording from Home (I wrote a script that will do this). I would then picked a site on the other side of the centerline and "go mobile" to that (using my 12-inch Sky-Watcher 300P and my Astrid). My thought was -- ~maybe~ one of the two sites would capture an event.
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First step... I made up a "timeline" of when things had to be done by (allowing some "fudge factoring" for any "issues").
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Home --?
I used my (absolute favorite!) star chart program Carte du Ciel to generate a pre-point line on a printed chart. I picked a time on the pre-point line (5:45:44UT - about 1:45am) that would be a an hour+ before the time of the event - giving me time to leave and "go mobile". I got the 14.5-inch scope in my Home observatory on the Target Star and found 30fps would easily capture it. I then moved the scope to the point on the pre-point line about 1.4 hours ahead (west) of the event. As the mount is fixed, I only had to move it westward in RA. Since I got on this point on the pre-point line about 10-minutes ""before"" I needed to, I let the drive run, tracking at this point on the pre-point line. At the indicated time on the pre-point line (5:45:44UT), I switched the drive off. But shortly before I was to have left to "go mobile" some rather thick fog rolled in. It was so thick, I somewhat questioned about continuing. Instead, I went back and changed the set exposure from 30fps to 15fps - in case the fog was thick at the time the automatic record kicked in. I then left to "go mobile" about 1 hour before the event time. Event time being 7:07:44UT (~3:08am).
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Mobile --
Took a 12 minute drive to get to the site. Got set-up and on the Target Star in about 30 minutes (the 12-inch is a GoTo Dob). It was a bit foggy there too (but fortunately the event was 67 degrees Up in the East - out of the horizon murk). I set my Astrid to record at 33fps (which my Astrid will do reliably with 0.00% timestamp error). To my delight, I captured an event! (and it later turned out to be 0.31 seconds duration - the maximum predicted was 0.33!).?
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Returning Home I checked the observatory (with a heavily dew-covered scope).... Upon playback in SER Player, the Target Star slowly moved toward the center of the FOV, and at nearly the very center of the frame, it briefly winked at me!!! I also captured a Pos from Home!!
[Turns out the duration was 0.13 seconds with 3 very distinct data points in the drop. At least 3 data points are required in most events for PyOTE to be able to "certify" an event is real]. The Target Star was bright(!) in the QHY recording, so it told me that the fog situation wasn't bad at the time the Home recording kicked in. I actually could have left it at 30fps as I originally planned - or maybe even done 50fps.
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A quick look at the observations (off the plots) shows the 'rough' center-time of the Mobile event to be 7:07:43.590 and the center-time of the Home event to be 7:07:43.760 - just as it should be (as the shadow was moving from south to north). The JPL predicted center-time was, again, 7:07:44UT +/-0 seconds.
From the two observations, it rather clearly defines where the path actually went (it shifted a tad west).
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Overall, technically, everything went as planned - no equipment / time issues.
When I finish and submit the reports on this event I'll now have __25__ Positive events awaiting review by the IOTA review folks.?
....And I have TWO nice events (mags 9.5 & 9.6!) tonight... but it will probably be cloudy - Sigh.
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Nice having luck on your side once in a while. Hope some might have enjoyed this saga.?
So this time.... Bullwinkle pulled a rabbit.
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G
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George Viscome
