The is a tough event with very low odds. We're doing it because the science payoff is high. Refining the orbit of Weywot will help us determine the mass of Quauor, among other possible benefits. The odds of a positve is only 2.6%. Normally I'd not attempt such an event, but... there's many other observers signed up so we'd like to help find this object!
Caveats: The duration for a central event is 4.3 seconds, and the drop is complete. This therefore should be do-able given clear skies. We will probably want to integrate at 32x or maybe even 64x. The value is in getting certainty of an occultation and getting the shape of Weywot will be too hard for an 8" scope. Just confirming an occultation is the value here. The altitude is 36 degrees so it's high enough to get. It forms a triangle with M16 and M17 diffuse nebulae, so if you can't identify the field, try just sending the scope to M16 and make sure the scope is aiming properly. Maybe do that first, even.
The time uncertainty is large. 4.1 minutes. So, I would suggest taping from 5 minutes before to 5 minutes after the predicted time.
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Kirk and I both got good recordings of the 14.5 magnitude star, at 32x, so that alone is nicely surprising. The gibbous moon was still 14 degrees up in the west, and I observed from Rincon St, with a big streetlight in the general direction. 64x would have been too bright a sky to succeed at all, so I backed off to 32x. The target was visible on about 3/4 of the integrations as I watched it live, but it was surprisingly consistently above sky on all the integrations. I observed from 6 minutes before to 4.2 minutes after the event, wanting to leave some time to get Ornamenta. Kirk informed me that B. Jones actually had a positive, and he wasn't that far from our locations, so our observations may yet be useful on constraining this Moon of Quouar.
Nolthenius light curves
First is sky (green) and target (blue). Second is just target (blue). I used the vertical median filter once again, to minimize trouble with the vertical bars. There was some wandering of the stars and in this case the vertical bars can cause more noise in the light curve. I used a static aperture placed on the target and two widely separated tracking stars to correct for any image rotation, given the long 10 minute recording time. I also had to do it a second time because the first time one of my tracking stars was within a box of another similar bright star and the software kept switching between stars.
32x setting on the Watec. Green is "sky", blue is target. |
Target alone. A central occultation was predicted to send 9 consecutive plot points to zero. I don't see more than 2 consecutive points at zero, so I interpret this as a miss. |
setting up, off the back of my RAV4, aimed the wrong way down a 1-way street.... it's the way I roll. At least, if the target is low in the south. |
Kirk's light curves
First is the PyMovie target, w/o combining sub-integration points. 2nd is the target (blue) and one of the tracking stars (green). Kirk's data looks cleaner and quieter than mine, once again. Perhaps he had a darker direction, looking over the ocean mostly from his end of town. Or, the Watec I've loaned him may just be better.
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Kirk's position was only 2 miles cross-track different than mine, and has a more convincting miss with quieter data.
