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Two positive chaords were recorded by John Broughton, one using drift scan and using video OSD technique.
He also observed a clearly observed miss at another station.
View the updated prediction.
Observers: 1 J Broughton,Reedy Creek, QLD, AU 2 J Broughton,Chinderah, NSW, AU 3(M) J Broughton,Pottsville, NSW, AU 4(P) Prediction, May 18
Discussion:
The ellipse above is plotted at the same area as expected circle of 86km and with maximum axis ratio as determined by lightcurve inversion data. With two chords we can be confident of the path of Magdalena and that it was north of the predicted line.
The figures below show the drift-scan image of the occultation (1) together and the data as analysed by John's Scanalyser software.
The figure below shows the light curve of John's occultation (2).
Observational Data:
Observation details for MP (318) Magdalena By Star TYC 5739-02067-1 On 2011-06-26 at 19:07:08.0 _______________________________ Observer John Broughton Location Reedy Creek, QLD, AU Longitude +153:23 Latitude -28:06 Altitude 66 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 25 cm Seeing Slight flickering Clear Camera Type Camera Delay Timing other Drift scan Disappearance 19:07:11.33 Reappearance 19:07:16.75 Comments: Unattended drift scan. The camera lacks a working shutter and couldn't be timed by the audio method. The timing was extrapolated from star trails taken hours earlier, based on differences in apparent celestial coordinates and CCD coordinates. _______________________________ Observer John Broughton Location Chinderah, NSW, AU Longitude +153:33 Latitude -28:15 Altitude 5 m Datum WGS84 Telescope SCT including Cass and Mak Aperture 9 cm Seeing Slight flickering Clear Camera Type Camera Delay Timing GPS - other linking Video with frame analysis Disappearance 19:07:13.02 Reappearance 19:07:13.66 Comments: WAT120N+ x8 -0.19 applied. My pre-pointed C90 was left unattended and was subject to partial dewing when I collected it two hours later. Evidently it needs a longer dew shield. Although the star appears fainter than intended, I believe that the short total disappearance seen on video is real and the lightcurve supports that. _______________________________ Observer John Broughton Location Pottsville, NSW, AU Longitude +153:33 Latitude -28:23 Altitude 7 m Datum WGS84 Telescope Newtonian Aperture 31 cm Seeing Slight flickering Clear Camera Type Camera Delay Timing GPS - time inserted Video with frame analysis Missed Comments: