Spectacular Maia Grazing Occultation observed east of Washington, DC April 1
The path shifted south almost 0.4 km from what was expected, so our 3 northernmost observers had a miss (no occultation)
Four good video recordings of the graze were obtained
Updated: 2006 April 3
Message written to Vince Sempronio giving information about the mostly successful efforts to record the Maia graze from Prince Georges County, Maryland. Some videos of the graze will be posted here late next week. Vince, Glad that you were able to get some totals, but sorry about your Maia miss. The weather was touch-and-go all day, but we were lucky in southern Bowie to be near the edge of the intermittent clouds (that skunked Jim Vail and some others farther west) and had a clear view of almost the entire Pleiades passage. For the Maia graze, we had at least a dozen stations in southern Bowie, but the two northernmost ones, like you, had no occultation, and two others had total equipment failures. I managed to get my scope & video set up in time to record the Electra disappearance in bright twilight, then set up Joan with video at the northernmost station. She recorded several total occultations that I missed while I helped get others set up across the graze path. I hurriedly set up another video station near the meeting intersection, and got it going with clock drive and another observer's WWV before rushing back to my station, and turning on the camcorder, only to see Maia and the time only about 10 seconds before the end of the graze observing period. So I didn't get the graze at my station, although I did record lots of total occultations during the rest of the passage afterwards. At least, the video at the meeting intersection obtained a spectacular record of the graze, but I think it's the only video of the graze we obtained, with WWV but unfortunately not with video time insertion. All the other successful observers were visual in our group, except for Bart Huxtable, who also obtained a video recording of the graze. Farther west, at the elementary school near Route 193, Don Gardner and Chuck Quintero video recorded the graze from locations about 200 yards apart in opposite corners of the large parking lot. At 11:30 PM 4/1/2006, you wrote: >i think i got about 10 events (total occultations), i didn't start >keeping score till after a few had happened. > >Maia seems to be negative from my locale even though i was between the >"gray" lines. do i not understand what the gray lines mean? i'll have >to replay the tape in slow-mo to see if there were any events so short >that i missed them visually. did anybody else have the same exerience >about 25% south of the northern gray line ? - You were set up correctly, and as noted above, two others in our group had a miss, also. Like with asteroidal occultations, there is still some uncertainty in the predictions of grazing occultations, which is why the observations are valuable. But the south shift we had for the Maia graze was a little larger than we've had for other grazes since the Hipparcos catalog greatly improved the positions of all the ZC stars; now the only real uncertainty is with the lunar profile. >as with gaithersburg, the clouds covered Atlas so i packed up and >headed home soon there after. > >After spending the last 9 months offering KIWI-OSDs, i thought i should >actually go out and try one! This was my first outing for occs >in....well, i think i can measure it in decades! it was great to see >that first star slip behind the moon. > >i was using an N5 with a 3.3 reducer, pc180 camera and i nabbed SAO >76188 at mag 8.7 i was impressed. the pc180 has a few bad pixels that >get confused as dim stars but otherwise all went well. > >i can hardly wait for the next Pleiades! - Our next good chance will be the morning of July 20, with the Moon a waning crescent 23% sunlit, but we won't have a bright graze going through the DC area like we had with Maia. There will be a graze that morning of 6.6-mag. ZC 562 that we can observe from the Eastern Shore (that path, #135 in the RASC Observer's Handbook, passes near Augusta, GA; Raleigh, NC; Richmond, VA; Cambridge, MD; Brooklyn, NY; New Haven, CT; Worchester, MA; and Portsmouth, NH). The best graze on July 20 will be of Alcyone (#133 in the RASC book, and also on my map in the Jan. issue of S&T) that starts near Wichita Falls, TX, then extends northeast to just s. of St. Louis; then near Lafayette, IN and across lower Michgan and the Bruce Peninsula in Ontario. Pre-event prediction information, with diagrams, lots of maps, and plans for the graze are here. David Dunham e-mail: home, dunham@starpower.net office, david.dunham@jhuapl.edu phones cell 301-526-5590; office 240-228-5609; home 301-474-4722