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Four positive occultations were recorded using Video OSD technique.
One clearly observed miss was recorded for this event
View the updated prediction.
Observers:
1 (C) G Hudson,Porirua, New Zealand
2 B Allen,Blenheim, NZ
3 G Blow, A Homes, homes,Carter Obs Wellington, NZ
4 L Field,Kaikoura,NZ
5 B Loader,Darfield,NZ
6(M) A Pennell,B Begg Obsrvatory Dunedin NZ
7(P) Prediction, 15 Sept
Discussion:
The ellipse above is plotted at the best fit axis ratio as determined by Occult. With 4 chords we can be confident of the path of Flora and that it was a little south of the predicted line. The 2 DAMIT 3D models have been overlaid on the measured ellipse below and show good fit. But they are not different enough to rule out either. There is a slight preference for the second one.
Gordon had so much wind shake that his result has to be treated as sort of Clouded Out. The Asteroid was visible throughout but as the mag drop was low at 0.4 and the image kept blurring and going out of the measurement aperture on both sides it was not possible to detirmine the times of any dip.
The figure below shows the Carter light curve of the occultation.
The figure below shows the Bill's light curve of the occultation.
The figure below shows Larry's light curve of the occultation.
The figure below shows the Brian's light curve of the occultation.
John Talbot reviewed all 4 positives for this event from the AVI or .LC file right through.
It is clear that all 5 were affected by wind at some level. The Tangra Rerun option
with apertures much bigger than original was used, 6 to 9 rather than the default 3 to 4 size.
This means that when shake takes the object out of circle with small aperture the
larger one can still treat it as star not nearby background. This cleaned up a lot of the noise.
When I first saw this data I was looking for evidence of double star.
But there is no evidence of a step long or flat enough to be sure.
When you look at the plot you will see that both Bill and Brian are close enough
to the edge to start getting graze effects and I think that is a more likely
explanation for the "Slow R" particularly,
The CSV data was run through Occular, AOTA, and R-OTE and they all give differing answers
, sometimes quite big differences.
Bill's and Brian's results were the first to be put into Occult and got a nice ellipse
that was a bit smaller than predicted area circle.
When I added Larry's data it was almost perfect fit with a chord not far from the centre.
Well done Larry for a first success. Keep it up.
When Carter team's chord was added it also was very close to the others.
ISAM and DAMIT were then checked and 2 rather similar 3D solutions were found,
The second one (DAMIT 110) is the best fit by a small margin.
Note the polar axis is close to pointing at Earth at the time in both models.
Overall a very good result - Well done team.
If the weather had been kinder in the Wellington area we might have got another 3 chords.
Observational Data:
Observation details for MP ( 8 ) Flora
By Star TYC 6905-02043-1
On 2013-10-25 at 08:27:29.0
_______________________________
Observer Bill Allen
Location Blenheim, NZ
Longitude +173:50
Latitude -41:29
Altitude 38 m
Datum WGS84
Telescope SCT including Cass and Mak
Aperture 40 cm
Seeing Slight flickering Clear
Camera Type WAT120N+ PAL/CCIR
Camera Delay 0.11
Timing GPS - time inserted Video with frame analysis
Disappearance 08:27:19.61
Reappearance 08:27:24.76
Comments: Datum NZ1949 (topographical map)
Times Revised after AOTA analysis by JT
_______________________________
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 Clear
Camera Type WAT120N+ PAL/CCIR
Camera Delay -0.07
Timing GPS - time inserted Video with frame analysis
Disappearance 08:27:08.41
Reappearance 08:27:11.04
Comments: Some wind shake, including very brief spells just before and early in event.
Report prepopulated by IOTA Reporting Add-in for OW ver.1.7
_______________________________
Observer A J Pennell
Location Beverly Begg Observatory Dunedin New Zealand
Longitude +170:29
Latitude -45:52
Altitude 136 m
Datum WGS84
Telescope SCT including Cass and Mak
Aperture 35 cm
Seeing Strong flickering Clear
Camera Type WAT120N PAL/CCIR
Camera Delay -0.05
Timing GPS - time inserted Video with frame analysis
Missed
Comments:
_______________________________
Observer Larry Field
Location Kaikoura
Longitude +173:41
Latitude -42:25
Altitude 70 m
Datum WGS84
Telescope SCT including Cass and Mak
Aperture 25 cm
Seeing Slight flickering Clear
Camera Type Other non integrating NTSC/EIA
Camera Delay 0
Timing GPS - time inserted Video with frame analysis
Disappearance 08:27:14.78
Reappearance 08:27:22.83
Comments: wind shake evident in Limovie LC images Times revised after AOTA analysis by JT Location assumed Home as reporte by Google Earth
_______________________________
Observer Graham Blow, John & Aline Homes
Location Carter Obs. Wellington, NZ
Longitude +174:46
Latitude -41:17
Altitude 129 m
Datum WGS84
Telescope SCT including Cass and Mak
Aperture 41 cm
Seeing Slight flickering Thin cloud < 2
Camera Type WAT120N+ PAL/CCIR
Camera Delay -0.05
Timing GPS - time inserted Video with frame analysis
Disappearance 08:27:22.937
Reappearance 08:27:29.057
Comments: thin cloud and wind Video analysed by John Talbot with Tangra V3.036 (Beta)
and times extracted using AOTA V 4.1.0.15 Only other star on screen visible for only part of record due cloud.
_______________________________
Observer G Hudson
Location Porirua, New Zealand
Longitude +174:50
Latitude -41:06
Altitude 52 m
Datum WGS84
Telescope SCT including Cass and Mak
Aperture 30 cm
Seeing Slight flickering Clear
Camera Type WAT120N+ PAL/CCIR
Camera Delay 0.35
Timing GPS - time inserted Video with frame analysis
Comments: Bad wind shake smearing imgage so no reult possible. Analysed with Tangra V3 and Limovie by JT