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A Four well spread chords were recorded by John Broughton, using video OSD technique.
One chord using a Canon D50 DSLR camera taking picture at approximately 1.3 second intevals was made by Stephen Mudge.
and another by Stephen Broderick using a video camera at Toowoomba.
And Five clearly observed misses were recorded. And a further 3 obsrvers had cloud or techincal problems.
View the updated prediction.
Observers: 1(M) D Watson,Thornton near Whakatane, NZ 2(M) P Anderson,THE GAP,Brisbane,QLD,AU 3(M) T.Napier-Munn,Brisbane, QLD,AU 4 S Mudge,Willowbank,QLD,AU 5 J Broughton,Reedy Creek, QLD, AU 6 J Broughton,Clothiers Creek, NSW, AU 7 S Broderick,Toowoomba, QLD,AU 8 J Broughton,Brunswick Heads, NSW, AU 9 J Broughton,Bangalow, NSW, AU 10(M) J Talbot,Waikanae Beach, NZ 11(M) M Forbes,Lower Hutt 12(P) Prediction, 04 July
Discussion:
The ellipse above is plotted at the best fit axis ratio of just the GPS timed chords. With 5 chords we can be confident of the path of Emanuela and that it was about 17 km north of the predicted line.
Sadly there is no Damit/ISAM/Miriade 3D model to help refine the analysis.
Light curve data had suggested a maximum axis ratio of only 1.05:1 but if we constrain the
ellispe by chord 3 then we have measured ratio about 1.52:1
Observational Data:
Observation details for MP ( 576 ) Emanuela By Star HIP HIP94645 On 2013-07-26 at 08:51:03.0 _______________________________ Observer John Talbot Location Waikanae Beach, NZ Longitude +175:01 Latitude -40:51 Altitude 5 m Datum WGS84 Telescope Newtonian Aperture 25 cm Seeing Slight flickering Clear Camera Type KPC-350BH PAL/CCIR Camera Delay 0 Timing GPS - time inserted Video with frame analysis Missed Comments: Clear, windy, On target, Definite miss. A two frame dip caused by wind shake but star reamins visible. Report prepopulated by IOTA Reporting Add-in for OW ver.1.7 _______________________________ Observer Diana Watson Location Thornton near Whakatane, NZ Longitude +176:51 Latitude -37:55 Altitude 3 m Datum Other Telescope SCT including Cass and Mak Aperture 200 cm Seeing Steady Clear Camera Type Camera Delay Timing Tape Recorder + time signal Visual, no PE applied Missed Comments: some ground mist _______________________________ Observer John Broughton Location Reedy Creek, QLD, AU Longitude +153:23 Latitude -28:06 Altitude 65 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 7 cm Seeing Slight flickering Clear Camera Type WAT120N+ PAL/CCIR Camera Delay 0.05 Timing GPS - time inserted Video with frame analysis Disappearance 08:54:36.26 Reappearance 08:54:46.50 Comments: Telescope prepointed several days in advance to provide time for setting up mobile stations in the early evening. _______________________________ Observer John Broughton Location Clothiers Creek, NSW, AU Longitude +153:31 Latitude -28:20 Altitude 15 m Datum WGS84 Telescope Refractor Aperture 3 cm Seeing Slight flickering Clear Camera Type Other integrating PAL/CCIR Camera Delay 0.07 Timing GPS - other linking Video with frame analysis Disappearance 08:54:34.83 Reappearance 08:54:44.35 Comments: Camera: LN-300-11673 This miniature recording station has a base sitting on a heavy paving stone set into the ground and prepointed 19 days in advance. That enabled it to be placed back in position during daylight, giving enough time in the dark to set up two stations further south. _______________________________ Observer John Broughton Location Brunswick Heads, NSW, AU Longitude +153:32 Latitude -28:32 Altitude 16 m Datum WGS84 Telescope Newtonian Aperture 10 cm Seeing Slight flickering Clear Camera Type Other integrating PAL/CCIR Camera Delay 0.05 Timing GPS - other linking Video with frame analysis Disappearance 08:54:34.31 Reappearance 08:54:42.03 Comments: Camera: LN-300-11673 _______________________________ Observer John Broughton Location Bangalow, NSW, AU Longitude +153:29 Latitude -28:42 Altitude 16 m Datum WGS84 Telescope Refractor Aperture 3 cm Seeing Slight flickering Clear Camera Type WAT120N+ PAL/CCIR Camera Delay 0.07 Timing GPS - other linking Video with frame analysis Disappearance 08:54:37.33 Reappearance 08:54:38.29 Comments: _______________________________ Observer Stephen Mudge Location Willowbank,QLD,AU Longitude +152:40 Latitude -27:41 Altitude 45 m Datum WGS84 Telescope Refractor Aperture 5 cm Seeing Steady Clear Camera Type Visual Other Camera Delay 0 Timing other Only duration timed Disappearance 08:54:25.16 Reappearance 00:00:34.85 Comments: Canon 50D and 70-200mm telephoto lens, capturing a series of 1 sec exposures at f/4 and 3200 iso A write up by Stephen Mudge of his observation can be found at Ice In Space John Broughton writes: After verifying the cadence and photometry of Stephen Mudge's images, the duration is now revised up to 9.87 +/- 0.18; a figure Stephen and I both agree on. The uncertainty is higher than the adjacent Reedy Creek chord because the reappearance is taken to have occurred in the middle of a 0.36s dead period when the camera was blind. John Talbot Notes: As Stephen was only able to accurately measure the elapsed time the absolute times of the D and R have been adjusted to align with John Broughton's nearly chord. This chord has been assigned a lower weight than the John's observations on account of the higher uncertainty and dependency on them for absolute timing. _______________________________ Observer Peter Anderson Location THE GAP,Brisbane,QLD,AU Longitude +152:55 Latitude -27:27 Altitude 170 m Datum WGS84 Telescope Newtonian Aperture 41 cm Seeing Steady Clear Camera Type Visual Camera Delay 0 Timing Tape Recorder + time signal Visual, PE applied Missed Comments: The area cleared of light cloud by the time monitoring began. Images were relatively steady. DEFINITELY NO EVENTS - A MISS _______________________________ Observer Murray Forbes Location Lower Hutt Longitude +174:58 Latitude -41:09 Altitude 25 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 20 cm Seeing Steady Clear Camera Type KPC-350BH PAL/CCIR Camera Delay 0 Timing GPS - time inserted Video with frame analysis Missed Comments: Report prepopulated by IOTA Reporting Add-in for OW ver.1.7 _______________________________ Observer Stephen Broderick Location Toowoomba, QLD,AU Longitude +151:55 Latitude -27:33 Altitude 620 m Datum WGS84 Telescope Aperture 0 cm Seeing Clear Camera Type Camera Delay 0 Timing other Video with frame analysis Disappearance 08:54:41.00 Reappearance 08:54:51.00 Comments: {times adjusted +6.5 sec to align with GPS timed chords jt) I videoed the occultation last night in Toowoomba. The star HIP94645 disappeared at 6:54:41 and reappeared at 6:54:51. (10 seconds). I can send the video if you need it. Thanks for the opportunity you presented me with after reading your article in Sky and Telescope. It was my first asteroid occultation so I was pretty happy with the results and process in general. Regards, Stephen Broderick, St Ursula´s College _______________________________ Observer Tim Napier-Munn Location Bellbowrie,Brisbane, QLD,AU Longitude +152:53 Latitude -27:33 Altitude 53 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 36 cm Seeing Slight flickering Clear Camera Type Visual Camera Delay 0 Timing Stopwatch Visual, no PE applied Missed