|
An 11.2 second occultation was recorded by Brian Loader, using video OSD technique.
View the updated prediction.
Observers: 1 B Loader,Darfield 2(M) B Allen,Blenheim, NZ 3(P) Prediction 5 April
Discussion:
The circle above is plotted at the expected 65 km diameter of Virtus.
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 measured
chord of about 87 km would suggest that the chord might lie close
to the central portion of the asteroid.
Note that there was a miss reported for Virtus on 2009 April 21 and another positive
just a week before this one on 2009 May 10.
Both positives had chords close to 87 km,
and were late by about 30 seconds in this case and 40 seconds late previously.
Observational Data:
Observation details for MP (494) Virtus By Star UCAC2 19229799 On 2009-05-17 at 13:09:17.0 _______________________________ Observer Brian Loader Location Darfield Longitude +172:06:24.4 Latitude -43:28:52.9 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 13:09:41.20 Reappearance 13:09:52.40 Comments: Watec 120N camera at 16 fold integration. Times partly by visual inspection of video and part using Limovie _______________________________ Observer Bill Allen Location Blenheim, NZ Longitude +173:50:21.4 Latitude -41:29:30. Altitude 38 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 40 cm Seeing Steady Clear Timing Tape Recorder + time signal Drift scan Missed Comments: Very good observing conditions temp 9.6, no wind.