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Four stations recorded positives for this event using video OSD technique and one clearly observed miss was recorded using visual observing. As the star proved to be a new double a total of 7 chords were recorded.
View the updated prediction.
Observers:
1(M) D Watson,Thornton near Whakatane, NZ
2 W Hanna,Alice Springs, NT,Australia
3 J Broughton,Pimpama, QLD, AU
4 J Broughton,Pimpama, QLD, AU
5 J Bradshaw,Samford Valley, Qld, AU
6 J Bradshaw,Samford Valley, Qld, AU
7 J Broughton,Reedy Creek, QLD, AU
8 J Broughton,Reedy Creek, QLD, AU
9(P) Prediction, 27 January
Six other observers ( Gordon Hudson, John Talbot, Terry Butt, Ross Skilton,
Dennis Lowe, and Rory O’Keefe ) had registered in Occult Watcher for this
event but were Clouded out.
Had it been fine at least 3 of these had a good chance of a positive recording.
Discussion:
The ellipse above is plotted at the best fit axis ratio as determined by Occult with line 8 R dropped from the calculation. With 7 chords we can be confident of the path of Undina and that it was slightly south of the predicted line.
The figure below shows Bill's Tangra light curve of the occultation.
The figure below shows Jonathan's Tangra light curve of the occultation.
The figure below shows John's mobile station Tangra light curve of the occultation.
The figure below shows John's Home Tangra light curve of the occultation.
As we can see Both John and Jonathan had a step on oth the D and R of their curves. This gives very strong evidence of a double star even though it had not previously been reported as such. The plot below shows the two stars chords separately and it became clear that Bill was just north of the shadow of the sencond star and this explains why his curve does not show any step.
Further analysis shows that the estimates of the magnitude of the two stars are somewhat ambiguous with Jonathan's data indicating that the second star is brighter, and John's data showing the first star brighter. Averageing the 3 resuts gives Star 1 magnitude 12.14 and Star 2 magnitude 12.11. The abiguitiy may possibly be explained by different spectral responses of the cameras used.
Observational Data:
Observation details for MP ( 92 ) Undina
By Star TYC 1950-00148-1
On 2013-02-06 at 11:55:17.0
_______________________________
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 20 cm
Seeing Steady Broken cloud
Camera Type WAT120N+ NTSC/EIA
Camera Delay 0.291666666666667
Timing GPS - time inserted Video with frame analysis
Disappearance 11:55:15.68
Reappearance 11:55:21.56
Comments: StellaCam 3 (Peltier-cooled WAT120N+) used; air temperature was 32 C. Light wind, no moon.
_______________________________
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 CCD PAL/CCIR
Camera Delay 0
Timing GPS - time inserted Video with frame analysis
Disappearance 11:53:22.56
Reappearance 11:53:24.30
Comments: Perfect conditions - close to edge, but nice clear event. Report prepopulated by IOTA Reporting Add-in for OW ver.1.7
_______________________________
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 CCD PAL/CCIR
Camera Delay 0
Timing GPS - time inserted Video with frame analysis
Disappearance 11:53:17.69
Reappearance 11:53:27.03
Comments: Perfect conditions - double star discovery and a longer than expected chord. 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:
_______________________________
Observer John Broughton
Location Pimpama, QLD, AU
Longitude +153:17
Latitude -27:48
Altitude 6 m
Datum WGS84
Telescope Newtonian
Aperture 32 cm
Seeing Slight flickering Clear
Camera Type WAT120N PAL/CCIR
Camera Delay 0.05
Timing GPS - other linking Video with frame analysis
Disappearance 11:53:16.23
Reappearance 11:53:23.47
Comments: One component of a double that produced the second D and (presumably) the first R. 0.915s subtracted from DVR time stamp to
equate to UTC.
_______________________________
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 WAT120N PAL/CCIR
Camera Delay 0.05
Timing GPS - time inserted Video with frame analysis
Disappearance 11:53:11.95
Reappearance 11:53:22.11
Comments: One component of a double that produced the first D and (presumably) the last R.
_______________________________
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 WAT120N PAL/CCIR
Camera Delay 0.05
Timing GPS - time inserted Video with frame analysis
Disappearance 11:53:13.78
Reappearance 11:53:20.98
Comments: One component of a double that produced the second D and (presumably) the first R.
_______________________________
Observer John Broughton
Location Pimpama, QLD, AU
Longitude +153:17
Latitude -27:48
Altitude 6 m
Datum WGS84
Telescope Newtonian
Aperture 32 cm
Seeing Slight flickering Clear
Camera Type WAT120N PAL/CCIR
Camera Delay 0.05
Timing GPS - other linking Video with frame analysis
Disappearance 11:53:13.83
Reappearance 11:53:23.43
Comments: One component of a double that produced the first D and (presumably) the last R. 0.915s subtracted from DVR time stamp to
equate to UTC.