A 4.5 second occultation was recorded by Hristo Pavlov, using video technique.

Dave Gault had a problematic observation for this event.

View the updated prediction.

Observers:
  1    D Gault,Hawkbury Heights, NSW,AU
  2    H Pavlov,Marsfield,NSW,AU
  3(P) Prediction 20 Oct 2009

Three other observers registered for the event but were clouded out.

    

Discussion:

The circle above is plotted at the expected 113 km diameter of Circe. With only one reliable chord it is not possible to determine whether Hristo was north or south of the central line of the event. However, assuming the updated prediction was approximately correct the slightly longer than expected chord of about 120 km would suggest that the chord might lie close to the central portion of the asteroid. Because he had to use very long x128 integration (~5 seconds) Dave effectively had only 5 data points, so his uncertainly is greater than the expected max duration.

The figure below shows Dave's light curve of the occultation and the Occular attempt to fit the data.

Observational Data:

Observation details for MP (34) Circe
By Star   UCAC2 25652532
On 2010-03-19  at 15:23:36.0

_______________________________

Observer   Dave Gault
Location   Hawkesbury Heights, Northern end of Booker Road
Longitude  +150:38:33.9
Latitude   -33:39:37.2
Altitude   277 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Strong flickering Thin cloud < 2
Timing     GPS - time inserted Video with frame analysis
Disappearance  15:23:43.00
Reappearance   00:00:00.00
Comments: I had the target star at 16 frame integration, but cloud obsured field
at about 15:20.  I increased exposure to 128 frames and gradulally the stars
reappeared and kept on getting brighter as seen in accompanying Tangra screenshots.
However the target star's brightness dropped at the central time stated above.

_______________________________

Observer   Hristo Pavlov
Location   Marsfield
Longitude  +151:06:13.
Latitude   -33:46:16.
Altitude   110 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Steady Thin cloud < 2
Timing     GPS - time inserted Video with frame analysis
Disappearance  15:23:38.05
Reappearance   15:23:42.57
Comments: WAT-120N+; Gamma = 0.45 (LO); x16 frame integration High cloud
Report prepopulated by IOTA Reporting Add-in for OW ver.1.4