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Updated: 2005 NOV 30, 05:12 UT
Event Rank : 96
(The event Rank is a measure of the likelihood of observing an event, and is equal to the probability of at least one successful observation by a team of two observers spaced 1/8 path width just inside opposite sides of the predicted path. An event rank of 100 indicates that the prediction is expected to be very accurate).
THE UPDATED PATH
Note: The duration given in the line below is the interval during which the occultation shadow sweeps across the Earth - please see the minute markers on the map to determine the approximate time for your location.
On 2005 Dec 09 UT, the 117 km diameter asteroid (1093) Freda will occult a 10.3 mag star in the constellation Lynx for observers along a path running up the south-western coast of Western Australia, passing over Bunbury, near Perth and Geraldton.
In the case of an occultation, the combined light of the asteroid and the star will drop by 4.3 mag to 14.6 mag (the magnitude of the asteroid) for at most 6.8 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Ron Stone, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC.
Additional details of this and other events are available at Steve Preston's website at http://www.asteroidoccultation.com/
EVENT DETAILS SUMMARY :Important Note regarding Accuracy:
The uncertainty interval in path widths given above (and shown as a 1-sigma uncertainty ellipse on the plot) refers to RMS deviation and is applied as a +/- range. In other words, a path uncertainty of 1.0 path widths means that the actual center of the asteroid's shadow path should fall within plus or minus 1 path width of the plotted path center. However path errors larger than 1 sigma have been observed so observers should be alert for primary occultations within plus or minus 3 sigma of the updated path.
Further, almost all asteroidal satellites discovered so far have been found within 10 diameters of the asteroid (since this distance is deep enough within the gravitational well to be stable over long timescales). Therefore, if monitoring for secondary events, observing out to about 10 path-widths either side of the predicted track remains worthwhile.
We therefore recommend that you monitor for events if your observing location is up to +/- 10 path-widths from the predicted track. If not monitoring for occultations by secondary bodies you should observe from locations within 3 sigma of the nominal path.
In terms of time, the predictions are now usually accurate to about +/- 0.3 minute so you should be most attentive during the predicted minute of the event. However if intending to catch a potential satellite occultation you should start observing at least 10 times the predicted central duration before the predicted closest approach time for your location, and continue for a similar period afterwards.
Centre Star Star Sun Path Limits Error Limits
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
115 23 43 -37 0 0 17 40 51 8 4 -27 116 42 44 114 2 22 117 47 27 112 52 1
115 9 49 -36 0 0 17 40 53 9 5 -28 116 28 14 113 49 5 117 32 27 112 39 16
114 53 55 -35 0 0 17 40 55 10 5 -29 116 11 49 113 33 42 117 15 38 112 24 19
114 36 3 -34 0 0 17 40 57 11 5 -30 115 53 33 113 16 14 116 57 1 112 7 11
114 16 14 -33 0 0 17 41 0 12 5 -31 115 33 25 112 56 42 116 36 37 111 47 55
113 54 27 -32 0 0 17 41 3 13 6 -32 115 11 26 112 35 8 116 14 27 111 26 30
113 30 44 -31 0 0 17 41 6 14 6 -33 114 47 35 112 11 30 115 50 29 111 2 55
113 5 3 -30 0 0 17 41 9 15 6 -34 114 21 53 111 45 48 115 24 44 110 37 11
112 37 22 -29 0 0 17 41 13 16 7 -35 113 54 17 111 18 1 114 57 10 110 9 14
112 7 41 -28 0 0 17 41 17 17 7 -36 113 24 46 110 48 5 114 27 46 109 39 4
111 35 55 -27 0 0 17 41 21 18 7 -37 112 53 18 110 15 58 113 56 30 109 6 35
111 2 2 -26 0 0 17 41 25 19 8 -38 112 19 49 109 41 36 113 23 19 108 31 44
110 25 58 -25 0 0 17 41 30 20 8 -39 111 44 16 109 4 54 112 48 8 107 54 25
109 47 37 -24 0 0 17 41 35 21 9 -40 111 6 35 108 25 47 112 10 56 107 14 32
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
[Asteroid Occultation Results]
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