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OCCULTATION OF UCAC2 21161679 BY 106 Dione
2008 June 03


A 1.11 second occultation was recorded by John Broughton, using CCD Drift scan technique.

View the Occult prediction.

View the Occult prediction.

Observers:
  1    J Broughton,Reedy Creek, QLD, Aus    
  2(P) Prediction 1-April                   

Dione occultation - 2008 June 03

Discussion:

The circle above is plotted at the expected 147 km diameter of Dione. With only one chord it is not possible to determine whether John was north or south of the central line of the event. However, assuming the prediction was approximately correct it would suggest that the chord might lie close to the southern portion of the asteroid.

The figures below show the drift-scan image of the occultation

Dione occultation - 2008 June 03

Observational Data:

Observation details for MP (106 ) Dione
By Star              UCAC2 21161679
On 2008-06-03  at 19:23:00.0
_______________________________

Observer   
Location   
Longitude  +153:23:52.8
Latitude   -28:06:30.3
Altitude   66 m
Datum      WGS84
Telescope SCT
Aperture   25 cm
Seeing     Steady Clear
Timing     Tape Recorder + time signal + shutter Drift scan
Disappearance  19:23:04.46
Reappearance   19:23:05.57
Comments: : A clearly positive result from a magnitude 12.5 occultation.
 The measured duration of 1.11 is remarkably short (9%) compared with the
maximum duration of 12 seconds. Supporting a grazing occultation scenario
where the star passed within 1km of the edge of Dione is the fact
that the event occurred only 5 seconds later than prediction.
On the other hand, if the occultation was caused by a Dione satellite,
then the best guess for its diameter is 17km, which represents a body
27% longer than the length of this random chord.
I should also mention that the apparent second gap in the trail
on the right is actually the end of the trail and beginning of another.    

Return to 2008 occultation results



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