A 4.60 second occultation was recorded by John Broughton, at Reedy Creek, Australia, using CCD Drift Field technique.

View the updated prediction.

Observers:
  1    J Broughton, Reedy Creek, Australia

Discussion:

The circle above is plotted at the expected 131km diameter of Lumen. With only one chord it is not possible to determine whether John was north or south of the central line of the event. The observation was longer than the predicted maximum which implies he was near the center and there is a possibilty of irregular shape. The predicted path was very close to his site.

The figures below show the drift-scan image of the occultation together with data as analysed by John's Scanalyser software.

Aperture (cm)                    : 25.4
Focal length (cm)                : 169
Type (e.g. SCT; Newtonian)       : SCT
Magnification                    : CCD drift-scan at 5 pps, 50'FOV 
Observing site name              : Reedy Creek, Gold Coast
Longitude (East +ve)             : +153 23' 49"
Latitude (South -ve)             : -28 06' 36"
Height above Sealevel (metres)   : 66
Geodetic Datum (e.g.WDD84,NZ1949): AGD66
Sky Transparency (Delete two)    : Good
Star Image Stability (Delete two): Fair
Other Conditions:                  
     (Wind, Clouds, Lights, etc.): 
Time Source (e.g. WWV, VNG)      : WWVH.
Recording method (e.g. tape)     : Tape.  
Could you see the Asteroid?      : Only combined light monitored.
Approx. Limiting Magnitude       : 12.5
                                          | Estimated  |
                           Universal Time | Reaction   | Accuracy, Remarks
                              h  m  s     | Time (sec) | 
   COLUMN FORMAT TO USE--->  __:__:__._        _._       _________________)
Started Observing          : 17:13:21.97       n/a       0.01
Disappearance At           : 17:13:38.44       n/a       0.10
Reappearance At            : 17:13:43.04       n/a       0.10
Stopped Observing          : 17:14:02.29       n/a       0.01
Duration                   :        4.60   

ADDITIONAL COMMENTS:  
Rigorously timed CCD drift-scan measured in Scanalyzer:
http://www.users.bigpond.com/reedycrk/driftscantiming.htm

The unpowered SCT was aligned on a 3rd magniude star at 13:17:13
when it had precisely the same azimuth as the occultation would have
some 4 hours later. The declination knob was adjusted -8.88 revolutions
to reach the correct altitude. I relied on an unreleased version of
Scantracker to output such information and display a zoomable 32-degree
altazimuth chart of the alignment star field. The scope was then covered
while I slept a few hours, safe in the knowledge it was already aligned. 

Under constant threat of showers, I didn't attach the camera until 16:40
and with overcast lasting until 17:09, there was no time to adjust focus.
The resultant blurred image has reduced sensitivity and the overall timing
accuracy not as high as otherwise would be the case.  

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