Double star evidence was recorded at two sites by Brian Loader and Stu Parker , using video OSD technique.

View the updated prediction.

Observers:
  1    B Loader,Darfield, NZ - Primary
  2    B Loader,Darfield, NZ - Secondary
  3    S Parker,Oxford, NZ - Primary
  4    S Parker,Oxford, NZ - Secondary
  5(P) Prediction 23 July


    

Discussion:

The circle above is plotted at the expected 37 km diameter of Tjilaki. With two obersevers and a double star chord it is possible to be confident that the plot represents a fairly accurate picture of the event. The ellipse of 37.7 x 36.4 km is a bit smaller than the predicted circle of 37 km. Provisional data based on magnitude variations on the Geneva University data base suggests an axis ratio of 1.14 vs. 1.04 drawn above.
More interesting is the "new" double star discovery. Despite its declination of -4 deg which suggests it should be a subject for lunar occultation it does not seem to appear in the normal ZC,SAO,XZ catalogs. The plot above has a separation of 1.7 milli arcseconds and PA of -87 degrees. I have not found any other reference to it being a double so for now we will assume that Brian and Stu are the first to observe it as double at least by occultation.

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

Observational Data:

Observation details for MP (732) Tjilaki
By Star              TYC 5186-00724-1
On 2009-07-28  at 12:42:37.0

_______________________________

Observer   B. Loader
Location   Darfield
Longitude  +172:06:24.
Latitude   -43:28:53.
Altitude   210 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   25 cm
Seeing     Slight flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  12:42:38.66
Reappearance   12:42:42.00
Comments:   Report prepopulated by OccultWatcher's Reporting Addin ver.1.2

_______________________________

Observer   B. Loader
Location   Darfield
Longitude  +172:06:24.
Latitude   -43:28:53.
Altitude   210 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   25 cm
Seeing     Slight flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  12:42:38.54
Reappearance   12:42:41.84
Comments: Star appears to be double.  Times for secondary
            D:  12:42:38.655±0.01,
            R  12:42:42.00±.03
Report prepopulated by OccultWatcher's Reporting Addin ver.1.2
_______________________________

Observer   Stuart Parker
Location   Oxford, NZ
Longitude  +172:13:8.
Latitude   -43:18:36.8
Altitude   221 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   30 cm
Seeing     Strong flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  12:42:37.70
Reappearance   12:42:40.02
Comments: Double Star
_______________________________
Observer   Stuart Parker
Location   Oxford, NZ
Longitude  +172:13:8.
Latitude   -43:18:36.8
Altitude   221 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   30 cm
Seeing     Strong flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  12:42:37.98
Reappearance   12:42:40.06
Comments: Double Star