A greater than 40.9 sec occultaion was observed By John Broughton at Reedy Creek, QLD.

View the updated prediction.

Observers:
  1 J. Broughton, Reedy Creek, QLD, Australia
  2 Pedicted 

Discussion:

The circle above is plotted at the expected 158km diameter of Chicago. With only one chord it is not possible to say which side of John's location the central path was, but his partial chord is much longer than expected for the diameter of a round object.

The figures below shows the drift-scan image of the occultation.

Observational Data:

Observer's Name                  : John Broughton
TELESCOPE DETAILS:
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): Poor due to wind.
Other Conditions:                  
     (Wind, Clouds, Lights, etc.): Low altitude 
TIMINGS:  (PLEASE REPORT IN UNIVERSAL TIME)
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--->  __:__:__._        _._       _________________)
Disappearance At           : not recorded
Started Observing          : 13:19:28.85       n/a       0.01
Reappearance At            : 13:20:09.78       n/a       0.1
Stopped Observing          : 13:21:09.66       n/a       0.01
Duration                   :     >=40.9  

ADDITIONAL COMMENTS:  
Drift scan recorded indoors through a SCT manually aligned on the previous
night with the aid of the altazimuth mode of ScanTracker.

As I was getting acceptable images, it was convenient to aim the telescope
through a fixed window rather than spend hours relocating everything.
I was mindful not to take a maximum-length exposure due to the low elevation.
At low elevation in populated areas you lose limiting magnitude not only
from extinction but also from an increase in skyglow.
A 90-second test exposure indicated a limiting magnitude only 1 magnitude
fainter than the star. For the occultation I chose an exposure of 100 seconds
which represented double the uncertainty plus the maximum duration.

Despite this, the image shows the occultation was already underway
at the beginning of the exposure. The attached image is centred on
reappearance and the visible trail to the left of reappearance
actually represents an unrelated 12.0-magnitude star.
What duration I did record lasted 9.8 seconds longer than the maximum
predicted, indicating the planetoid has a long axis of at least 198km. 

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