A 28.9 second occultation was recorded by Jonathan Bradshaw, using Video OSD technique.
Two clearly observed misses were recorded for this event.
View the updated prediction.
Observers: 1 J Bradshaw,Samford Valley, Qld, AU 2(M) J Broughton,Reedy Creek, QLD, AU 3(M) S Kerr,Rockhampton,QLD,AU 4(P) Prediction27 Jan
The circle above is plotted at the expected 158 km diameter of Wratislavia.
With only one chord and John Broughton's nearby constraining miss we can be sure that Jonathan was East
of the central line of the event.
The ISAM 3D model has been overlaid on the measured circle but with only one chord we cannot be sure of the relative scale.
June 2013 Updated. Following another Wratislavia occultation which also gave abiguity it was noted that there was a second positive for this event observed by M Owada, Hamamatsu, Shizuoka, Japan.
The updated observer list is now: 1 J Bradshaw,Samford Valley, Qld, AU 2(M) J Broughton,Reedy Creek, QLD, AU 3(M) S Kerr,Rockhampton,QLD,AU 4(P) Prediction27 Jan 5 M Owada, Hamamatsu, Shizuoka, Japan 6(M) R Aikawa, Sakado, Saitama, Japan
The extra chord resolves the amibuity in favour of model #2 with the NE-SW spin. This is noted in the 2013 March 11 event write up for the same object.
The figure below shows the Limovie/Tangra light curve of the occultation.
Observation details for MP ( 690 ) Wratislavia By Star TYC 6133-00477-1 On 2013-02-11 at 15:33:40.0 _______________________________ Observer Jonathan Bradshaw Location Samford Valley, Qld, AU Longitude +152:50 Latitude -27:22 Altitude 80 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 36 cm Seeing Steady Clear Camera Type G-Star PAL/CCIR Camera Delay 0 Timing GPS - time inserted Video with frame analysis Disappearance 15:33:08.55 Reappearance 15:33:37.43 Comments: Perfect Conditions, and a nice gentle curve seen on D and R. Report prepopulated by IOTA Reporting Add-in for OW ver.1.7 _______________________________ Observer John Broughton Location Reedy Creek, QLD, AU Longitude +153:23 Latitude -28:06 Altitude 66 m Datum WGS84 Telescope Newtonian Aperture 32 cm Seeing Slight flickering Clear Camera Type WAT120N PAL/CCIR Camera Delay 0.03 Timing GPS - time inserted Video with frame analysis Missed Comments: _______________________________ Observer S. Kerr Location Rockhampton,QLD,AU Longitude +150:30 Latitude -23:16 Altitude 50 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 30 cm Seeing Slight flickering Clear Camera Type WAT120N+ PAL/CCIR Camera Delay 0.05 Timing GPS - time inserted Video with frame analysis Missed Comments: Report prepopulated by IOTA Reporting Add-in for OW ver.1.7