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A possible 3.78 sec occultaion was measured by Andrew Dallow using drift scan with a 6 inch scope.
The prediction for this event was posted on the OZNZ site monitored by OccultWatcher.
View the updated prediction.
Observers: 1(M) P Loader,Darfield, NZ 2(M) B Loader,Glentunnel,NZ 3 A Dallow,Darfield,NZ 4(M) L Hussey,Christchurch, NZ 5(P) Predcited OZNZ 18 Sept
Discussion:
The circle above is plotted at the expected 7 km diameter of Masamura. With only one chord it is not possible to determine whether Andrew was north or south of the central line of the event.
The figures below show the drift-scan image of the occultation together and the data as analysed by Andrew's Scanalyser software.
The second copy of the image has be enlarged 200% and brightened which makes it easier to see that the dip is more probably noise than the asteroid. Masamura was predicted to have a magnitude of 15.3 and a magnitude drop of 8.6 which would be expected to be too dim to show on the image with a 15cm telescope. All observers have reported flickering and one also noted high cloud.
The graph also shows a noisy signal with several dips to similar readings of the possible event.
The following graph is the observation for track 1 very close to Andrew's.
On balance all the observations are probably negative.
Observational Data:
_______________________________ Observation details for MP (4614) Masamura By Star HIP HIP700 On 2007-10-30 at 11:50:07.0 _______________________________ Observer Pauline and Brian Loader Location Darfield, NZ Longitude +172:06:24.4 Latitude -43:28:52.9 Altitude 210 m Datum WGS84 Telelscope SCT including Cass and Mak Apperture 25 cm Seeing Slight flickering Clear Timing GPS - other linking Video, photo or photoelectric Missed Comments: No event observed. _______________________________ Observer Lionel Hussey Location 24 Takaro Avenue, Sockburn, NZ Longitude +172:33:23.6 Latitude -43:32:6.3 Altitude 47 m Datum WGS84 Telelscope SCT including Cass and Mak Apperture 20 cm Seeing Slight flickering Thin cloud < 2 Timing Radio broadcast - calibrated Visual, no PE applied Missed Comments: City light pollution could be seen faintly on high cloud _______________________________ Observer Brian Loader Location Glentunnel Longitude +171:48:23.3 Latitude -43:31:1.8 Altitude 322 m Datum WGS84 Telelscope SCT including Cass and Mak Apperture 20 cm Seeing Strong flickering Clear Timing GPS - time inserted Video, photo or photoelectric Missed Comments: No event observed. Strong wind shake at times. _______________________________ Observer Andrew Thomas Dallow Location Darfield Longitude +172:04:5. Latitude -43:28:59. Altitude 205 m Datum WGS84 Telelscope Newtonian Apperture 15 cm Seeing Slight flickering Clear Timing Stopwatch Drift scan Disappearance 11:50:04.51 Reappearance 11:50:08.29 Comments: Star was dim in my telescope May have some Fresnel diffraction