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Updated: 2006 SEP 20, 17:16 UT
Event Rank : 58
(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 2006 Oct 20 UT, the 54 km diameter asteroid (1731) Smuts will occult a 10.2 mag star in the constellation Orion for observers along a significant uncertainty path beginning near Exmouth in Western Australia, running across central Australia, western and southern New South Wales, passing near Canberra and leaving near Cape Howe on the NSW/Victoria border.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.2 mag to 15.4 mag (the magnitude of the asteroid) for at most 11.8 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
153 43 52 -41 0 0 16 52 20 30 21 -21 152 59 4 154 28 3 151 20 2 156 1 33
152 39 50 -40 0 0 16 51 49 31 23 -22 151 54 47 153 24 15 150 15 4 154 58 7
151 33 46 -39 0 0 16 51 18 31 24 -23 150 48 21 152 18 30 149 7 43 153 52 56
150 25 27 -38 0 0 16 50 45 32 26 -25 149 39 34 151 10 37 147 57 43 152 45 50
149 14 40 -37 0 0 16 50 11 32 28 -26 148 28 10 150 0 22 146 44 47 151 36 37
148 1 7 -36 0 0 16 49 35 32 29 -28 147 13 52 148 47 31 145 28 35 150 25 3
146 44 29 -35 0 0 16 48 59 33 31 -29 145 56 18 147 31 44 144 8 41 149 10 52
145 24 22 -34 0 0 16 48 20 33 33 -31 144 35 3 146 12 39 142 44 33 147 53 45
144 0 17 -33 0 0 16 47 40 33 35 -32 143 9 34 144 49 51 141 15 32 146 33 20
142 31 37 -32 0 0 16 46 59 33 37 -34 141 39 11 143 22 45 139 40 47 145 9 10
140 57 37 -31 0 0 16 46 15 33 39 -36 140 3 3 141 50 40 137 59 11 143 40 40
139 17 16 -30 0 0 16 45 30 33 41 -38 138 20 1 140 12 43 136 9 10 142 7 7
137 29 13 -29 0 0 16 44 42 32 43 -40 136 28 32 138 27 42 134 8 31 140 27 38
135 31 33 -28 0 0 16 43 51 31 46 -42 134 26 20 136 34 0 131 53 51 138 40 59
133 21 27 -27 0 0 16 42 57 31 48 -44 132 9 59 134 29 15 129 19 24 136 45 29
132 0 0 -26 25 45 16 42 24 30 50 -45 -26 55 53 -25 56 4 -28 2 35 -24 53 21
131 0 0 -26 2 9 16 42 1 29 51 -46 -26 31 59 -25 32 44 -27 38 2 -24 30 34
130 0 0 -25 39 53 16 41 38 29 52 -47 -26 9 27 -25 10 43 -27 14 53 -24 9 4
129 0 0 -25 18 57 16 41 15 28 53 -48 -25 48 17 -24 50 2 -26 53 7 -23 48 52
128 0 0 -24 59 20 16 40 53 28 53 -49 -25 28 26 -24 30 39 -26 32 44 -23 29 57
127 0 0 -24 41 2 16 40 32 27 54 -49 -25 9 54 -24 12 33 -26 13 42 -23 12 17
126 0 0 -24 24 1 16 40 11 26 55 -50 -24 52 41 -23 55 44 -25 56 0 -22 55 52
125 0 0 -24 8 17 16 39 51 26 56 -51 -24 36 45 -23 40 11 -25 39 38 -22 40 41
124 0 0 -23 53 48 16 39 32 25 57 -52 -24 22 6 -23 25 52 -25 24 34 -22 26 44
123 0 0 -23 40 34 16 39 13 24 58 -52 -24 8 42 -23 12 48 -25 10 48 -22 13 59
122 0 0 -23 28 35 16 38 55 24 58 -53 -23 56 34 -23 0 57 -24 58 18 -22 2 26
121 0 0 -23 17 49 16 38 37 23 59 -53 -23 45 39 -22 50 19 -24 47 5 -21 52 4
120 0 0 -23 8 15 16 38 20 22 60 -54 -23 35 58 -22 40 53 -24 37 6 -21 42 53
119 0 0 -22 59 54 16 38 3 21 60 -55 -23 27 30 -22 32 38 -24 28 22 -21 34 52
118 0 0 -22 52 43 16 37 47 21 61 -55 -23 20 13 -22 25 34 -24 20 51 -21 28 0
117 0 0 -22 46 44 16 37 32 20 62 -55 -23 14 8 -22 19 40 -24 14 33 -21 22 17
116 0 0 -22 41 54 16 37 18 19 62 -56 -23 9 13 -22 14 55 -24 9 27 -21 17 41
115 0 0 -22 38 13 16 37 4 18 63 -56 -23 5 28 -22 11 18 -24 5 32 -21 14 13
114 0 0 -22 35 41 16 36 51 17 63 -56 -23 2 53 -22 8 50 -24 2 48 -21 11 52
113 0 0 -22 34 18 16 36 38 16 64 -57 -23 1 26 -22 7 29 -24 1 15 -21 10 37
112 0 0 -22 34 1 16 36 26 16 64 -57 -23 1 7 -22 7 15 -24 0 50 -21 10 28
Use these links for further information:
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[Observing Details]
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