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OCCULTATION OF UCAC4_390_060062 BY 19 Fortuna
2015 April 24

A 14.8 second occultation was recorded by Brian Loader, using video OSD technique.

No clearly observed misses were recorded for this event.

View the updated prediction.

  1    B Loader,Darfield                    
  2(P) Prediction.Personal April 24         


Fortuna occultation__ 2015 April 24


The circle above is plotted at the expected 230 km diameter of Fortuna. With only one chord it is not possible to determine whether Brian was north or south of the central line of the event. The Damit 3D model has been overlaid on the measured circle.

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

Fortuna occultation__ 2015 April 24

The noise level in this curve is quite high but the measured chord could fit the DAMIT model with an offset of +/- 50 km so it must be considered as at very least a "probable" positive. With the DAMIT and Tangra estimate of probability together I think this can with confidence be treated as a Positive observation.

Observational Data:

Observation details for MP ( 19 ) Fortuna
By Star              UCAC4 390-060062
On 2015-04-24  at 11:50:31.0


Observer   B. Loader
Location   Darfield
Longitude  +172:06
Latitude   -43:28
Altitude   210 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   25 cm
Seeing     Slight flickering Thin cloud < 2 
Camera Type  WAT910BD       AAV-PAL       
Camera Delay -0.04
Timing     GPS - time inserted Video with frame analysis
Disappearance  11:50:14.19
Reappearance   11:50:28.99
Comments: Occult Prediction: combined mag 10.7, expected d mag 0.06 (5%), 
Event T max 17.2 sec, Pred time error 6s,  Prob of event 83% Tangra:  signal only used, 
normalised with comparison star, x8 binning applied.

Return to 2015 occultation results

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