There were 4 reports with possible positves recorded for this event.

View the updated prediction.

Observers:
  1    D Herald,Kambah, ACT,AU
  2    D Gault,Hawkesbury Heights,NSW,AU
  3    H Pavlov,St Clair, NSW, Australia
  4(M) S Russell,Oatlands, NSW, AU
  5(M) C Wyatt,Walcha, NSW, Australia
  6(P) Prediction TT14 31 Jul

    

Discussion:

It appears that the path has shifted slightly North of the predicted path.
The ellipse above is plotted at the best fit to the 3 chords it touches.
The chords 1-3 have been reviwed and meet the criteria of:
- the magdrop being consistent with the predicted value.
- the curve is a U shape
- the bottom has several points that are at that level.

Chord 4 has 3 possible "events". The mag drop is only about 20% of the expected value. The one shown is that which best fits the others. This is the earliest and least like an expected dip (see below).
The Light Curve Data Base shows a maximum elongagtion of about 1.6 compared to the drwan 2.12.
The star was faint and close to Polyxena in brightness so magnitude drop was expected to be about 0.7. All chords were observed using integrating cameras. Chord 4 used x32 integrating, 2&3 used x 8, but chord 1 used only x4. It is possible that a short dip of a few frames may have got lost in the longer integration.

I think this gives a lesson that where you are using an integrating type camera you should use the minimum integration setting that allows you to see the combined magnitude of the targets. Longer integrations will result in lower accuracy and possible loss of an event. You may want to consider using long integration while locating the target then wind back until you can just see the target.

I have used Occular to analyse the light curve data to try to ensure that the methodology was consistent. The results are shown below before time delays due to integration time have been applied.

The figures below shows the light curve of the occultation as interpreted by Occular.

Dave Herald x4

Dave Gault x8

Hristo Pavlov x8

Steve Russell x32

Observational Data:

Observation details for MP (595) Polyxena
By Star              UCA 2U12769883
On 2010-08-28  at 14:20:00.0

_______________________________

Observer   Hristo Pavlov
Location   St Clair, NSW, Australia
Longitude  +150:46
Latitude   -33:48
Altitude   68 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Steady Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:19:41.30
Reappearance   14:19:47.76
Comments: Integ x8 Time estimated by Occular

_______________________________

Observer   Stephen RUSSELL
Location   Oatlands, NSW, AU
Longitude  +151:01
Latitude   -33:49
Altitude   60 m
Datum      WGS84
Telescope Newtonian
Aperture   20 cm
Seeing     Slight flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:19:45.43
Reappearance   14:19:46.84
Comments: Very short event possibly spurious
Integ x32
Times from Occular analysis of first dip

_______________________________

Observer   Chris Wyatt
Location   Walcha, NSW, Australia
Longitude  +151:50
Latitude   -31:01
Altitude   1237 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Slight flickering Thin cloud < 2
Timing     Tape Recorder + time signal Visual, no PE applied

Missed

Comments: A difficult observation, the atmospheric scintillation made target
star visible then undetectable in periods of bad seeing.
Added to the visual difficulty was an inquisitive bull on the property which
made me a little concerned during the minute of the occultation prediction,
I think the beeper box had something to do with it.
Also, thin cloud coming from the SE decided to block my view on and off through
the occultation, I could not be certain of a positive result.

_______________________________

Observer   Dave Herald
Location   Kambah, ACT,AU
Longitude  +149:03
Latitude   -35:23
Altitude   582 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   35 cm
Seeing     Steady Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:19:24.77
Reappearance   14:19:26.93
Comments: Integrating 4 frames
Report prepopulated by IOTA Reporting Add-in for OW ver.1.5
Note asymmetry between D and R
_______________________________

Observer   Dave Gault
Location   Hawkesbury Heights,NSW,AU
Longitude  +150:38
Latitude   -33:39
Altitude   286 m
Datum      WGS84
Telescope Newtonian
Aperture   25 cm
Seeing     Slight flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:19:42.41
Reappearance   14:19:50.09
Comments: Light curve and .csv file included with this report.
Integration x8
Occular D=14:19:42.456 R=49.806