A 4.16 second occultation was recorded by Brian Loader, using Video OSD technique.

View the updated prediction.

Observers:
  1    B Loader,Darfield, NZ
  2(P) Prediction, 19 April


        

Discussion:

The circle above is plotted at the expected 49 km diameter of Petropolitana. With only one chord it is not possible to determine whether Brian was north or south of the central line of the event. However, assuming the updated prediction was approximately correct the close to expected maximum chord of about 45 km would suggest that the chord might lie close to the central portion of the asteroid.

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

Observational Data:

Observation details for MP ( 830 ) Petropolitana
By Star              TYC 6161-00910-1
On 2012-05-30  at 16:17:30.0

_______________________________

Observer   B. Loader
Location   Darfield, NZ
Longitude  +172:06
Latitude   -43:28
Altitude   210 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   25 cm
Seeing     Strong flickering Clear
Camera Type  WAT120N        PAL/CCIR
Camera Delay 0.09
Timing     GPS - time inserted Video with frame analysis
Disappearance  16:17:28.79
Reappearance   16:17:32.95
Comments:   Report prepopulated by IOTA Reporting Add-in for OW ver.1.6