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OCCULTATION OF UCAC2 30028442 BY 18 Melpomene
2008 August 21


A 3.9 second occultation was recorded by John Broughton, using CCD drift scan technique.

View the updated prediction.

Observers:
  1    J Broughton,Reedy Creek, QLD 4227, AU
  2(P) Prediction 25 July
    

Melpomene occultation - 2008 August 21

Discussion:

The circle above is plotted at the expected 140 km diameter of Melpomene. With only one chord it is not possible to determine whether John was north or south of the central line of the event.

The figure below shows a compund drift-scan image - See comments below.

Melpomene occultation - 2008 August 21

Observational Data:

Observation details for MP (18 ) Melpomene
By Star              UCAC2 30028442
On 2008-08-21  at 08:19:45.0
_______________________________

Observer   J Broughton
Location   Reedy Creek,Reedy Creek, QLD 4227, Australia
Longitude  +153:23:52.8
Latitude   -28:06:30.3
Altitude   66 m
Datum      WGS84
Telescope Newtonian
Aperture   51 cm
Seeing     Steady Broken cloud
Timing     Tape Recorder + time signal + shutter Drift scan
Disappearance  08:19:46.80
Reappearance   08:19:50.70

COMMENTS:
This small 0.36-magnitude drop event was imaged through cloud.
To demonstrate what's going on, I compiled an image of 5 aligned trails.
In the original image, the top trail was located NW of the occulted trail,
the bottom one SE and all trails were scattered in that general direction
in the same order as the aligned image. In the aligned image, attenuations
caused by cloud move toward the right going from top to bottom and the
right-hand ones fade out. The occultation trail (4th from top) bucks
the trend near in its centre in a way expected for a positive event.
The places I measured D and R in that 4th trail are indicated by arrows
and result in a 3.9s duration - plausibly 70% of the maximum predicted.

    

Return to 2008 occultation results



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