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OCCULTATION OF UCAC2 26788716 BY 3317 Paris
2010 August 17


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

    

Paris occultation - 2010 August 17 Paris occultation - 2010 August 17

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.

Paris occultation - 2010 August 17

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.

Paris occultation - 2010 August 17

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. Paris occultation - 2010 August 17

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.

    

Return to 2010 occultation results



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