A 46.8 second occultation was recorded by Peter Graham, using video OSD technique. This event involved a very shallow dimming during the occultation that was faintly but distinctly recorded by Peter's video system. Diana Watson also monitored this event by visual means and did not observe an occultation although it is likely that the dimming was too small for her to detect. As such, it does not offer a confirming or constraining observation to that observed by Peter.
View the Personal prediction.
Observers: 1(M) D Watson,Thornton near Whakatane, NZ 2 P PBGraham,Martinborough, NZ 3(P) Prediction - 2015 Aug 22
The circle above is plotted at the expected 960 km diameter of Ceres. More accurate data on the size and shape of (1) Ceres is of course available from the current Dawn spacecraft mission. With only one chord it is not possible to determine whether Peter was north or south of the central line of the event although it is more likely that he was south of it as indicated by the prediction. Diana's observation does not constrain this conclusion.
The figures below shows the AOTA analysis of the light curve of Peter's observation.
Observation details for MP ( 1 ) ceres By Star TYC 6933-00036-1 On 2015-07-05 at 08:18:42.0 _______________________________ Observer Diana Watson Location Thornton near Whakatane, NZ Longitude +176:51 Latitude -37:55 Altitude 3 m Datum Other Telescope SCT including Cass and Mak Aperture 200 cm Seeing Steady Clear other - list in comments Camera Type Visual Other Camera Delay Timing Tape Recorder + time signal Visual, no PE applied Missed Comments: Target star fairly low so was not able to see it till it had cleared the trees, hence did not see merging. This would not be a miss but drop in magnitude too low to see visually. _______________________________ Observer PBGraham Location Martinborough, NZ Longitude +175:29 Latitude -41:14 Altitude 73 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 25 cm Seeing Slight flickering Thick cloud > 2 recording very faint. Camera Type Watec 910BD PAL/CCIR Camera Delay Timing GPS - time inserted Video with frame analysis Disappearance 08:18:25.48 Reappearance 08:19:12.29 Comments: A difficult recording lots of cloud after a clear beginning. I believe I had 2F integration set but the data seems to be not integrated.