A 2.3 second occultation was recorded by Murray Forbes, using Video OSD technique.

Two clearly observed misses were recorded for this event.

View the updated prediction.

Observers:
  1(M) G McKay,Blenheim, NZ
  2(M) B Allen,Blenheim, NZ
  3    M Forbes,Lower Hutt, NZ
  4(P) Prediction, 24 Feb

       

Discussion:

The ellipse above is plotted with major axis at 71 km and area the same as expected diameter of 54 km. The resulting axis ratio of 1.73 is much greater than the estimated ratio of 1.14 as determined by lightcurve data. This suggests that the size of Oceana has been significantly under estimated and that an eqivalent diameter of at least 66 km might be closer to reality.
With only one chord it is not possible to determine whether Murray was north or south of the central line of the event. However, assuming the updated prediction was approximately correct the longer than expected chord of about 71km would suggest that the chord might lie close to the central portion of the asteroid.

The figure below shows the Limovie light curve of the occultation.

Observational Data:

Observation details for MP (224) Oceana
By Star              TYC 6898-01810-1
On 2012-03-17  at 17:45:49.0
_______________________________

Observer   Murray Forbes
Location   Lower Hutt, NZ
Longitude  +174:58
Latitude   -41:09
Altitude   26 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Slight flickering Broken cloud
Camera Type  KTC530         PAL/CCIR
Camera Delay 0
Timing     GPS - time inserted Video with frame analysis
Disappearance  17:45:54.60
Reappearance   17:45:56.88
Comments: With the camera adjusted to maximum gain, star could be just seen although
if the event had been ten minutes later the star would have been lost in the
brightening twilight. Nevertheless, the occultation was clearly seen.
However the star was very difficult to see on the recording during the subsequent
Limovie analysis, hence the larger than normal uncertainties in the D and R.
_______________________________

Observer   Bill Allen
Location   Blenheim, NZ
Longitude  +173:50
Latitude   -41:29
Altitude   38 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   40 cm
Seeing     Slight flickering Clear
Camera Type
Camera Delay
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: Datum NZ1949 (topographical map) Good observing conditions air mass 1.5 Video with GPS

_______________________________

Observer   Graeme McKay
Location   Blenheim, NZ
Longitude  +173:57
Latitude   -41:32
Altitude   18 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Steady Clear
Camera Type  WAT120N        PAL/CCIR
Camera Delay 0.05
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: Observed a miss  Report prepopulated by IOTA Reporting Add-in for OW ver.1.6