|
A 1.92 second occultation was recorded by John Broughton, using video OSD technique.
Jonathan Bradshaw recorded a very short and possibly spurious event.
Both events were about 40 seconds later than predicted.
View the TT14 prediction.
Observers: 1 J Bradshaw,Samford,QLD,AU 2 J Broughton,Reedy Creek, QLD, AU 3(P) Prediction 31 July TT14
Discussion:
The circle above is plotted at the expected 116 km diameter of Paris. The ellipse above is plotted at the same area as the circle.
The Observatoire de Genève database suggests a lumpy profile but not elongated enough to fit with Jonathan's spike below.
The figure below shows the Tangra light curve of the occultation.
There was quite of lot of discussion about this set of data but I have to make a conservative decision. With only one certain chord it is not possible to determine whether John was north or south of the central line of the event and the final report shows the circle centred on John's location.
However Jonathans data is recored here should future observations be able to demonstrate the shape as as long and thin.
Observational Data:
Observation details for MP (3317) Paris By Star UCAC2 26788716 On 2010-08-17 at 11:58:07.0 _______________________________ Observer Jonathan Bradshaw Location Samford,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 Timing GPS - time inserted Video with frame analysis Disappearance 11:58:48.03 Reappearance 11:58:48.23 Comments: Very short but visually quite obvious event occuring 40 seconds late. I have subtracted 60ms which is my estimate of the camera lag, but the margin of error may be as high as +/- 60ms _______________________________ Observer John Broughton Location Reedy Creek, QLD, AU Longitude +153:23 Latitude -28:06 Altitude 66 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 25 cm Seeing Steady Thin cloud < 2 Timing GPS - time inserted Video with frame analysis Disappearance 11:58:41.01 Reappearance 11:58:42.93 Comments: Watec 120N+ using 8-frame integration.