A 2.85 second occultation was recorded by Dean Hooper, using Video OSD technique.

One clearly observed miss was recorded for this event.

View the updated prediction.

Observers:
 1(M) J Milner,Bayswater, VIC, AU          
  2    D Hooper,Melbourne, VIC, Australia        
  3(P) Prediction 11-Feb                          


        

Discussion:

The circle above is plotted at the expected 45 km diameter of Dorothea. With only one chord it is not normally possible to determine whether Dean was north or south of the central line of the event. However, with Jacquie's constraining miss we can be confident of the path of Dorothea and that it was south of the predicted line.

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

Dean notes that the Reappearance was slower than disappearance. There at least two possible explanations for this.
1. The Dorothea has an irregular shape so that star had near graze at R side.
Or 2. The star may be a very close double. As the R seems fairly linear
with no obvious step It seems that the first option is more likely.
Sadly there is not yet a DAMIT 3D model so we can not test this option.

Observational Data:

Observation details for MP ( 339 ) Dorothea
By Star              TYC 0828-01165-1 
On 2015-03-18  at 13:43:39.0

_______________________________

Observer   Jacquie Milner
Location   Bayswater, VIC, AU
Longitude  +145:14
Latitude   -37:50
Altitude   110 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Slight flickering Clear other - list in comments
Camera Type  Mintron 12V1C-EX             PAL/CCIR      
Camera Delay -0.04
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: Nice clear, still, autumn night. 
Supposedly some aurora happening to the south but unable to see it visually 
through the light pollution. 
Prediction in OccultWatcher had me under the shadow but recorded a miss, 
indicating a shift to the south.   

_______________________________

Observer   Dean Hooper
Location   Melbourne,VIC, Australia
Longitude  +145:00
Latitude   -37:56
Altitude   28 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Steady Clear 
Camera Type  WAT910HX       PAL/CCIR      
Camera Delay -0.05
Timing     GPS - time inserted Video with frame analysis
Disappearance  13:43:44.66
Reappearance   13:43:47.51
Comments: Tangra v3.3.8 / AOTA v4.1.4.3
 Reappearance was slower than disappearance.