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OCCULTATION OF TYC 5270-01385-1 BY 893 Leopoldina
2010 August 30


Four positive chords and 3 misses were recorded for this event.

View the updated prediction.

Observers:
  1(M) J Bradshaw,Samford,QLD,AU
  2    J Broughton,Reedy Creek, QLD,AU
  3    J Broughton,Chinderah, NSW
  4    D Herald,Yass,NSW,AU
  5    P Purcell,Murrumbateman, NSW,AU
  6(C) A Brakel,3.1 km N of Gundaroo, NSW,AU
  7(M) D Herald,Kambah, ACT,AU
  8(P) Prediction  21 July


    

Leopoldina occultation - 2010 August 30

Discussion:

The ellipse above is plotted at the best fit to the 4 observed chords. This gives a slightly smaller area than the predicted circle of 76 km. With 4 chords we can be confident of the path of Leopoldina and that it was North-East of the predicted line. The Light Curve Database gives a maximum axis ratio of about 1.38 which is in good agreement with the measured value of 1.32.

The figures below show the drift-scan image of the occultation together and the data as analysed by John's Scanalyser software.

Leopoldina occultation - 2010 August 30

Leopoldina occultation - 2010 August 30

The figure below shows the light curve of the occultation as seen by Patrick Purcell - he was clouded on either side but had a lucky break during the event.

Leopoldina occultation - 2010 August 30

Observational Data:

Observation details for MP (893) Leopoldina
By Star              TYC 5270-01385-1
On 2010-08-30  at 14:27:44.0

_______________________________

Observer   John Broughton
Location   Chinderah, NSW
Longitude  +153:33
Latitude   -28:15
Altitude   5 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   25 cm
Seeing     Steady Broken cloud
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:27:53.80
Reappearance   14:28:01.70
Comments: Watec 120N+ at 8x integration.

_______________________________

Observer   Dave Herald
Location   Yass,NSW,AU
Longitude  +148:57
Latitude   -34:52
Altitude   525 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Slight flickering Broken cloud
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:29:07.22
Reappearance   14:29:14.84
Comments: Cloud was a problem, but the light curve came through....
Report prepopulated by IOTA Reporting Add-in for OW ver.1.5

_______________________________

Observer   Jonathan Bradshaw
Location   Samford,QLD,AU
Longitude  +152:50
Latitude   -27:22
Altitude   80 m
Datum      WGS84
Telescope Newtonian
Aperture   36 cm
Seeing     Steady Clear
Timing     GPS - time inserted Video with frame analysis

Missed

Comments:   Report prepopulated by IOTA Reporting Add-in for OW ver.1.4

_______________________________

Observer   Dave Herald
Location   Kambah, ACT,AU
Longitude  +149:03
Latitude   -35:23
Altitude   582 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   35 cm
Seeing     Steady Clear
Timing     GPS - time inserted Video with frame analysis

Missed

Comments:   Report prepopulated by IOTA Reporting Add-in for OW ver.1.5

_______________________________

Observer   Patrick Purcell
Location   Murrumbateman, NSW,AU
Longitude  +148:59
Latitude   -34:57
Altitude   608 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Strong flickering Broken cloud
Timing     GPS - time inserted Video with frame analysis
Disappearance  14:29:08.13
Reappearance   14:29:15.29
Comments: Clouds: intruded just prior to 14h 26m UT.
Intermittent clearing fortunately included a 'window' for about 30 seconds at
exactly the right time.  The light curve shows a definite drop in brightness
at a time when the brightness should have peaked as the cloud cleared briefly.
I have attached the light curve.
How lucky was this? Clouds obscured the field just a few minutes before the
predicted event.  Fortuitously the cloud thinned out at the critical time
permitting this light curve from Murrumbateman.
I think I have used up all my good luck for the next decade!

_______________________________

Observer   Albert Brakel
Location   23.1 km N of Gundaroo, NSW,AU
Longitude  +149:14
Latitude   -34:49
Altitude   619 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Slight flickering Thin cloud < 2
Timing     Tape Recorder + time signal Visual, no PE applied

Missed (clouded)

Comments: A mag 11 star in moonlight was always going to be difficult visually
(but possible), but thin cirrus wisps forming in the region at the critical
time  caused the star to be invisible at the predicted time.
For what it's worth, the star was just visible from 14:28:06 to 14:29:09,
and then for very  brief glimpses at 14:29:41 and 14:30:09.
The lat/long of the site is that given by a car GPS.

_______________________________

Observer   John Broughton
Location   Reedy Creek, QLD,AU
Longitude  +153:23
Latitude   -28:06
Altitude   66 m
Datum      WGS84
Telescope Newtonian
Aperture   51 cm
Seeing     Steady Clear
Timing     other Drift scan
Disappearance  14:27:56.95
Reappearance   14:27:59.94
Comments: Unattended drift scan.

    

Return to 2010 occultation results



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