This is an unusually brilliant star, and even more remarkable, it has a good RUWE=1.05. This means the prediction is most likely reliable from a star position standpoint. However, the star is not a UCAC4 catalog star. I do not know if that's a warning sign or a good thing.
The asteroid orbit rank is good, but not as perfect as a low-numbered asteroid orbit would be. Still, this asteroid was discovered 27 years ago and so I'm guessing its orbit is likely known pretty well, even if the shape and other characteristics may still be less well known. This gives us a good opportunity to nail down the shape and size of the asteroid better, and perhaps even find a moonlet. We should most definitely expose this at the shortest integration possible, namely 1x for our Watec cameras. Since the new Astrid only goes down to 1/30s from what Kirk Bender tells me, this is not optimal. Perhaps Bernard's gear will even take exposures of much shorter duration and faster cadence?
So far, the only other observer I see is Bob Jones from Running Springs, CA in the eastern LA Basin area. I'm hoping that other SoCal observers will want to jump in too, if only for the opportunity of getting a record brilliance star in their video collection. The V-R is 1.0, which is decently on the reddish side, and makes our detector chips good choices.
Alt=46, Az=249, high in the SW. The target is just 2 degrees directly above Regulus. Use Regulus as one of your align stars.
Time: Event time on the Big Sur Coast is 10:23:56pm. At the Jolon Rd sites, at 10:24:00pm
From David Dunham on the IOTA Message board: May 20, 5:24 UT: Occultation of 4.7mag 37 Leonis = ZC 1504 =SAO 99034 = HIP 50333 by 4.4-km (28030) 1998 DW12, s. Calif (Bradley, Shandon, Taft, Fontana, Calipatria), Yuma, AZ. The asteroid diam. is 9 mas with a central event duration of 0.5s. With the star diam 2 mas (computed with the Warner relation), it will take 0.1s to cover star at the contacts, and the 11km-wide path will have partial zones 2 km wide at each limit. The RUWE is 1.05 (ok). The OWC link is https://cloud.occultwatcher.net/event/1600-2803.0-145623-648855-J4071418 .
Star position uncertainty: C2A has in their "Object Type" box the wording "6 - astrometric position is poor". That's more what I'd expect for such a bright star. But yet the RUWE is a low 1.05 which is comfortably inside the limit criteria of RUWE=1.20 above which is where star position error is not so good. I've posted a question on IOTA Message Board asking which to believe: C2A or RUWE? Dave H answered, that the source to absolutely trust is the GAIA data which gives RUWE=1.05, and that's good. Forget the C2A positional statement.
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