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
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.
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 v18.104.22.168 Reappearance was slower than disappearance.