|
|
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
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 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.