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Updated: 2005 NOV 30, 06:12 UT
Event Rank : 27
(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 12 UT, the 21 km diameter asteroid (1613) Smiley will occult a 9.6 mag star in the constellation Leo for observers along a path across central Western Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.2 mag to 14.8 mag (the magnitude of the asteroid) for at most 4.8 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
131 47 44 -37 0 0 18 53 14 33 9 -10 131 36 16 131 59 11 130 39 16 132 55 22
131 3 25 -36 0 0 18 52 50 34 10 -11 130 52 1 131 14 48 129 55 17 132 10 42
130 18 30 -35 0 0 18 52 25 35 11 -12 130 7 8 130 29 50 129 10 38 131 25 29
129 32 56 -34 0 0 18 51 59 36 12 -13 129 21 36 129 44 14 128 25 15 130 39 41
128 46 39 -33 0 0 18 51 32 36 13 -14 128 35 20 128 57 55 127 39 6 129 53 15
127 59 36 -32 0 0 18 51 5 37 14 -16 127 48 18 128 10 51 126 52 6 129 6 6
127 11 43 -31 0 0 18 50 36 38 16 -17 127 0 25 127 22 59 126 4 12 128 18 12
126 22 56 -30 0 0 18 50 7 39 17 -18 126 11 38 126 34 13 125 15 21 127 29 28
125 33 11 -29 0 0 18 49 37 39 18 -19 125 21 52 125 44 29 124 25 26 126 39 51
124 42 23 -28 0 0 18 49 7 40 20 -21 124 31 1 124 53 43 123 34 23 125 49 15
123 50 27 -27 0 0 18 48 35 41 21 -22 123 39 2 124 1 50 122 42 6 124 57 35
122 57 17 -26 0 0 18 48 2 41 23 -23 122 45 47 123 8 44 121 48 30 124 4 47
122 2 46 -25 0 0 18 47 29 42 24 -25 121 51 11 122 14 18 120 53 27 123 10 44
121 6 47 -24 0 0 18 46 55 42 26 -26 120 55 7 121 18 25 119 56 50 122 15 20
120 9 13 -23 0 0 18 46 20 43 27 -28 119 57 25 120 20 59 118 58 30 121 18 26
119 9 55 -22 0 0 18 45 44 43 29 -29 118 57 58 119 21 49 117 58 17 120 19 56
118 8 42 -21 0 0 18 45 7 44 31 -31 117 56 36 118 20 46 116 56 1 119 19 40
117 5 24 -20 0 0 18 44 28 44 33 -32 116 53 5 117 17 39 115 51 28 118 17 27
115 59 46 -19 0 0 18 43 49 44 35 -34 115 47 13 116 12 15 114 44 24 117 13 6
114 51 34 -18 0 0 18 43 9 44 37 -35 114 38 45 115 4 18 113 34 32 116 6 22
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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