Five well spaced complete chords and one R only were recorded using video OSD technique.

One observer was in the path but had technical problems.

View the Occult prediction.

View the last Paris prediction.

Observers:
  1    W Hanna,Alice Springs, NT,AU
  2    J Bradshaw,Samford Valley, Qld, AU
  3    I Curtis,Adelaide, SA, AU
  4(C) C Chad,Gunnedah, NSW, AU
  5    T Barry et al, Penrith Obs, NSW,AU
  6    H Pavlov,St Clair, NSW, Australia
  7    T Dobosz,Bankstown, NSW,AU
  8(P) Prediction, Occult, 13 Aug

        

Discussion: This was a difficult observation mainly due to the low magnitude drop, which was only 0.12 as Pluto was about 2 magnitude brighter than the star. So we cannot expect the details that we could see in the 2008 June 08 event that the Occsec team observed.

The circles above are plotted at the best fit ratio as determined by Occult to the Outer, Mid and Inner points on the light curves. The 3 separate plots have been aligned using transparent overlays with the Predicted line as a target. The outer one is 2952 km, the Mid one is 2717 km, and the Inner one is 2452 km, compared to the expected diameter of Pluto of 2306 km. With 5.5 chords we can be confident of the path of Pluto and that it was about 650 km North of the Occult predicted line.

The figures below show the light curves of the occultation.

These two are from Bill Hanna in Alice Springs. He had changed the integration time in the middle so the D and R have been separately processed.

Next is Jonathan Bradshaw from Samford Valley, QLD.

Then Ivan Curtis in Adelaide, South Australia, who used his CCD camera.

Then a team led by Tony Barry using the Universiy of Western Sydney, Penrith Observatory. Their R time seems early compared to Hristo's (below) and there is an interesting high point about 40 seconds later which may be the correct R but Occular give a poorer statistcal fit.

Hristo had a problem that prevented him observing the D but his R is quite clear.

Chris Chad recorded data but started about 6 minutes too late and while there is an interesting rise just at the start it does not have sufficient flat on each side to be sure it is an R.

Ted Dobosz's recording had high noise level but after re abalysis by Hristo using Tangra and use of Occular we were able to get a convincing curve.

In summary this was a sucessful team effort of a difficult target. Well done all.

Observational Data:

Observation details for MP ( 134340 ) Pluto
By Star              UCAC3 141-302444
On 2012-08-26  at 10:47:00.0
_______________________________

Observer   William Hanna
Location   Alice Springs, Australia
Longitude  +133:53
Latitude   -23:42
Altitude   581 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   36 cm
Seeing     Steady Clear
Camera Type  WAT120N+       PAL/CCIR
Camera Delay 1.31
Timing     GPS - time inserted Video with frame analysis
Disappearance  10:49:52.00
Reappearance   10:52:36.00
Comments: There was a distinct separation between Pluto and the target star.
Light wind.  71% moon 9 degrees away.
Assistance with setting up the 14" was provided by Richard Williamson, Paul Nitschke, and Andrew Crouch.
Time estimated with Occular from Tangra analysis
Ds= 10:49:40, Dm=10:49:52, De=10:50:03 --- Rs=10:51:48, Rm=10:52:36. Re=10:53:03
______________________________

Observer   Jonathan Bradshaw
Location   Samford Valley, Qld, Australia
Longitude  +152:50
Latitude   -27:22
Altitude   80 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   36 cm
Seeing     Steady Clear
Camera Type  G-Star         PAL/CCIR
Camera Delay 0.17
Timing     GPS - time inserted Video with frame analysis
Disappearance  10:46:54.00
Reappearance   10:50:59.00
Comments: Time estimated with Occular from Tangra analysis

Ds=10:46:33, Dm=10:46:55, De=10:47:03 - Rs=10:50:46, Rm=10:50:54, Re=10:51:04
Report prepopulated by IOTA Reporting Add-in for OW ver.1.6

_______________________________

Observer   Ivan Curtis
Location   Adelaide, South Australia
Longitude  +138:37
Latitude   -34:53
Altitude   45 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture  210 cm
Seeing     Slight flickering Thin cloud < 2
Camera Type
Camera Delay
Timing     other Video, photo or photoelectric
Disappearance  10:49:12.00
Reappearance   10:53:13.00
Comments: Image sequence taken with Atik320E CCD camera, exposure of 15s. Magnitude dip of 0.22mag seen.


_______________________________

Observer   Chris Chad
Location   Gunnedah, NSW, AU
Longitude  +150:15
Latitude   -30:59
Altitude   315 m
Datum      WGS84
Telescope Newtonian
Aperture   25 cm
Seeing     Slight flickering Thin cloud < 2
Camera Type  Other integrating            NTSC/EIA
Camera Delay 0.183
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: SCB-2000 (modded).  Not 100% sure have the right star,
but definitely the correct field. No events apparent.
{Data was rerun but while there is a possible R at the right time right at the
start there is insufficient bottom data to be sure it is real. - jt}

_______________________________

Observer   Tony Barry, Patrick Barry, Dave Gault, Joe Seychell
Location   UWS-Penrith Observatory, NSW,AU
Longitude  +150:44
Latitude   -33:45
Altitude   56 m
Datum      WGS84
Telescope other - specify below
Aperture   60 cm
Seeing     Steady Clear
Camera Type  Other integrating            PAL/CCIR
Camera Delay 0
Timing     GPS - time inserted Visual, PE applied
Disappearance  10:47:37.95
Reappearance   10:51:08.95
Comments: Telescope is a Classical Cassegrain.  Focal length - not sure.
Camera system was ADVS.
Analysis Tangra followed by blocking to 10 sec samples then Occular time estimates.
UWS=University of Western Sydney - Penrith Observatory
Ds=10:47:32, Dm=10:47:37, De=10:47:44 - Rs= 10:51:02 ,Rm=10:51:08, Re=10:51:14
Interesting exra R at about 40 seconds after reported R but rejected as probably spurious noise.

_______________________________

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   35 cm
Seeing     Steady Thin cloud < 2
Camera Type  WAT120N        PAL/CCIR
Camera Delay 0.33
Timing     GPS - time inserted Video with frame analysis
Disappearance  00:00:00.00
Reappearance   10:50:51.00
Comments: Missed the start of the occultation.
R from atmsphere was at 10:51:30 +/- 2 sec
 Rs=10:50:51+/- 2 sec , Rm=10:51:15+/- 4 sec ,Re=10:51:40  +/- 2 sec

Hristos details 
Report prepopulated by IOTA Reporting Add-in for OW ver.1.6
_______________________________

Observer   Ted Dobosz
Location   Bankstown, NSW,AU
Longitude  +151:01
Latitude   -33:55
Altitude   25 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   28 cm
Seeing     Strong flickering Star faint
Camera Type  KPC-350BH      PAL/CCIR
Camera Delay 0
Timing     GPS - time inserted Video with frame analysis
Disappearance 10:47:54.2
Reappearance 10:51:21.4
Comments: { Times rerun by Hristo Pavlov and then use of Occular from 1 second blocking of data.
Earlier analyses had been inconclusive. - jt}