May 5th Nanon Occultation Video Recorded in Connecticut
New: 2005 May 7On the evening of May 5th, I wrote the following message to Steve Preston, and copied it to the IOTAoccultations e-group and many potential observers in and near the predicted path for the occultation of 9.7-mag. TYC 6287-01516-1 by (559) Nanon that occurred that morning: Your predicted path apparently was very accurate; Charles Quintero and I drove to a mostly-dark (and cold, near freezing, strange while viewing the summer sky!) school parking lot north of Guilford, Connecticut, at long. 72 deg. 41.242' W., lat. 41 deg. 19.687' N, height 75 ft. and video recorded a long occultation there by (559) Nanon. The occultation occurred about 20 seconds earlier than predicted, but the path accuracy is encouraging for the Nanon occultation of an even brighter star, mag. 8.6, that will occur in s. California the day before the IOTA meeting, on July 1. Our location was close to your central line; we wanted to be north of Frank Suits' possible chord from Garrison, NY, and south of a possible observation from Glastonbury, CT. Charles and I wanted to set up two stations, and we could have done that if we had observed farther west. But shortly after midnight when we were in northern New Jersey and had to decide whether to drive north into the Hudson Valley, or farther east, I called the national weather service; the forecaster there said the clouds to the west were moving east as predicted, and that they expected it to be overcast over New York City half an hour after the event; he said we'd have better chances for clear sky in eastern Connecticut. It took more time to drive there, find a suitable site (Connecticut is filled with trees and houses with little dark, open space) and then more time to get all the equipment running and find the target star, so I didn't have time to find a second site and set up. Frank Suits said it was clear in the direction of the target star in Sagittarius from Garrison, NY at event time; too bad his camera failed so that he couldn't get an observation. But he said a cloud bank moved over the area before the event, and that might have foiled us if we had observed from the Hudson Valley area. Farther north, closer to the central line, Eric Bram tried to observe from Poughkeepsie but was hopelessly clouded out there, confirming that the Hudson Valley was not a good place to try the event (farther west, at Ithaca, Bruce Thompson also was clouded out). As we left Guilford in brightening twilight, we could see quite a few cirrus clouds to the north, although the full Moon stayed clear and bright until it was only a few deg. above the s.w. horizon; sorry that the clouds moved in earlier for Don in the Philadelphia area (that was way too far south for an occultation by Nanon, but certainly good for checking for satellite occultations, and a good dry run for the similarly bright star that Happelia will occult in s. Penn. on May 23). So far, I haven't heard of any other observations of this occultation, which is disappointing. Jim Carlson's report from Cape Cod was north of the predicted path (almost to the 1-sigma n. limit, but I think the error was half a sigma or less) so that he had a miss. He mentioned a dimming ten minutes before the predicted time (we started recording just over 5 minutes before the predicted time), but that was certainly not the main occultation since the mag. drop was deep (star completely disappeared) for us - the event was not in steps, and the complete drop also argues against the star being double); ten minutes represents over 30 Nanon diameters from the object, a distance unlikely to be stable enough for satellites, virtually all of the known ones of which are within 10 asteroid diameters. The 9.7-mag. target star was relatively bright with my PC-164C attached to a C8 with f/3.3 focal reducer. 11th-mag. stars were easy to see in spite of the full Moon 55 deg. away and the approximately 30 deg. altitude; I could see a few stars on the monitor not on the Millennium Star Atlas (that is, not in the Tycho-1 catalog). I'll determine preliminary event times and post them here soon. David Dunham At 03:22 PM 5/4/2004 -0700, Steve Preston wrote: I would like to encourage observers for tonight's event with (559) Nanon. If you are within roughly 100km of either edge of the predicted path, please try to monitor the star for this event. In addition to providing data on the asteroid, if we "catch" this event we have a good opportunity to contribute to some interesting research in ground based astrometry.