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A 2.01 second occultation was recorded by John Broughton at Reedy Creek, Qld, Australia, using the CCD drift-scan technique.
View the updated prediction.
Observers: 1 J. Broughton, Reedy Crk, Australia
Discussion:
The circle above is plotted at the expected 72km diameter of Iphigenia. With only one chord it is not possible to determine whether John was north or south of the central line of the event. However, assuming the updated prediction was approximately correct would suggest that the chord might lie across the northern portion of the asteroid as shown.
The figures below show the drift-scan image of the occultation together with data as analysed by John's Scanalyser software.
Observational Data:
Observer's Name : John Broughton
Aperture (cm) : 50.1
Focal length (cm) : 138
Type (e.g. SCT; Newtonian) : F/2.7 modified newtonian
Magnification : CCD drift-scan at 4.1 pps, 60'FOV
Observing site name : Reedy Creek, Gold Coast
Longitude (East +ve) : +153 23' 49"
Latitude (South -ve) : -28 06' 36"
Height above Sealevel (metres) : 66
Geodetic Datum (e.g.WDD84,NZ1949): AGD66
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions: Gibbous moon
(Wind, Clouds, Lights, etc.):
Time Source (e.g. WWV, VNG) : WWVH.
Recording method (e.g. tape) : Tape.
Could you see the Asteroid? : Only combined light monitored though
asteroid is visible during occultation.
Approx. Limiting Magnitude : 14.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 16:12:46.91 n/a 0.01
Disappearance At : 16:13:06.46 n/a 0.04
Reappearance At : 16:13:08.47 n/a 0.04
Stopped Observing : 16:13:27.26 n/a 0.01
Duration : 2.01
ADDITIONAL COMMENTS:
Rigorously timed and measured CCD drift-scan by methods described here:
http://www.users.bigpond.com/reedycrk/driftscantiming.htm
The measured duration lasted only 19% of the maximum predicted.
For a graze by a round asteroid, the viewpoint would have to be
from only 1% inside the edge of the path.