A Three chords were recorded , using Video OSD technique.

One clearly observed miss was recorded for this event.

View the updated prediction.

Observers:
  1(M) G Hudson,Porirua, New Zealand        
  2    M Forbes,Lower Hutt                  
  3    M Unwin,Wanaka, New Zealand          
  4    A Pennell, Dunedin, New Zealand
  5(P) Prediction, 01 April                 

        

Discussion:

The ellipse above is plotted at the best fit axis ratio as determined by Occult. With 3 chords we can be confident of the path of Aspasia and that it was north of the predicted line. The Damit/ISAM 3D model has been overlaid on the measured ellipse and shows poor fit. This has turned out to be quite a difficult event to sort out and even now the result is only partially satisfactory. The main problem is that the star was faint (mag 12.7) and the mag drop was small (0.2 m) All observers were using long integration times (x32 to x64 frames = 1.28 to 2.56 secs) so the time resolution is poor even when measured using AOTA and R-OTE. I have checked and rechecked Gordon's data and cannot find anything that is a convincing dip. The other 3 observers have dips that are consistent with the expected mag drop but all seem to show slow D and R. It seems that the major source of noise is in the Analogue cables and the A to D converter. All observers are to be congratulated in end up with data that is of sufficient accuracy to get a reasonable match with the DAMIT model.

The figure below shows the Tangra light curve of Martin's occultation as analysed by AOTA for the main event.

Observational Data:

Observation details for MP ( 409 ) Aspasia
By Star              UCAC4 492-144257
On 2014-08-30  at 14:50:37.0

_______________________________

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     Slight flickering Clear
Camera Type  WAT120N+       PAL/CCIR
Camera Delay -0.19
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:50:35.89
Reappearance   14:50:42.53
Comments: Lightcurve generated by Limovie. Occult's AOTA used to analyse event, 
giving the large uncertainties in the times.  
Report prepopulated by IOTA Reporting Add-in for OW ver.1.8

_______________________________

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     Steady Clear
Camera Type  WAT120N+       PAL/CCIR
Camera Delay -0.05
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: Video scan by Limovie Time analysis by AOTA 

_______________________________

Observer   Martin Unwin
Location   Wanaka, New Zealand
Longitude  +169:06
Latitude   -44:41
Altitude   300 m
Datum      WGS84
Telescope Newtonian
Aperture   15 cm
Seeing     Steady Clear
Camera Type  WAT120N        PAL/CCIR
Camera Delay -0.67
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:51:26.06
Reappearance   14:51:41.74
Comments: Video scanned with Limovie and times extracted using AOTA.
Line of sight just above roof of house, seeing affected by thermals.   
Report prepopulated by IOTA Reporting Add-in for OW ver.1.8

_______________________________

Observer   Ash Pennell
Location   Dunedin NZ
Longitude  +170:29
Latitude   -45:52
Altitude   136 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   35 cm
Seeing     Slight flickering Clear
Camera Type  WAT120N+       PAL/CCIR
Camera Delay -1.31
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:51:26.30
Reappearance   14:51:36.82
Comments: Times by Aota Tangra  scan