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OCCULTATION OF [star] BY 267 Chariklo
2015 May 12


A 9 second occultation was recorded by Jonathan Bradshaw, using video OSD technique.

One clearly observed miss was 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(P) Prediction, Rio Update, 2 May        
  4    J Bradshaw,Probable Ring
  5    J Bradshaw,Probable Ring
   
Another 6 observers further south  registered in OW:
Jacquie Milner, Dean Hooper, John Newman, Hristo Pavlov, Tony Barry, and Dave Gault
all were clouded out and would have seen a miss

        

Chariklo occultation__ 2015 May 12

Discussion:

The circle above is plotted at the expected 258 km diameter of Chariklo. With only one chord and John's constraining miss we can be confident of the path of Chariklo and that it was well north of the predicted line.

The figure below shows the Limovie light curve of Johnathan's occultation.

Chariklo occultation__ 2015 May 12 Chariklo is unusual in that it has previously been observed to have a ring system (see Prediction) The lightcurve above shows two short blips that would normally be considered noise but when we compare the prediction to the observed plot then we can see that the green dots on the path are highly likely to be caused by the rings.

Observational Data:


Observation details for MP ( 10199 ) Chariklo
By Star              UCAC4 267-150325
On 2015-05-12  at 17:56:41.0

_______________________________

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 Clear 
Camera Type  WAT120N+       PAL/CCIR      
Camera Delay -0.35
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: Star IAG, NIMA3 ephem. The 9s positive at Samford indicates I should 
have either a miss or a 16s positive. With the star visible in most 0.64s integrations,
 it most definitely was a miss. Regarding potential ring occultations, the star was too faint 
for a 10 telescope to capture events of short duration with any certainty.

_______________________________

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     Strong flickering Clear 
Camera Type  G-Star         PAL/CCIR      
Camera Delay -0.19
Timing     GPS - time inserted Video with frame analysis
Probable Ring  17:55:27.7
Disappearance  17:55:35.19
Reappearance   17:55:44.15
Probable Ring  17:55:57.1

Comments: Very poor seeing required longer (8 frame) integration. 
Whilst the occultation was clearly visible, the combination of seeing and 
integration meant that the rings were not as clearly detected. 


        

Return to 2015 occultation results



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