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Updated: 2011 JAN 27, 10:02 UT
Event Rank : 18
(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 2011 Feb 03 UT, the 40 km diameter asteroid (297) Caecilia will occult a 11.2 mag star in the constellation Auriga for observers along a narrow but quite uncertain path beginning near Rockhampton in Queensland. The path moves south-west through central Australia and into South Australia ending near Ceduna.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.9 mag to 15.0 mag (the magnitude of the asteroid) for at most 4.5 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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
123 13 13 -42 0 0 12 9 17 16 14 -11 122 42 33 123 44 5 118 57 11 127 43 54
124 14 15 -41 0 0 12 9 9 17 13 -12 123 43 39 124 45 4 119 58 53 128 44 44
125 16 43 -40 0 0 12 9 1 18 12 -13 124 46 8 125 47 31 121 1 42 129 47 21
126 20 42 -39 0 0 12 8 53 19 11 -15 125 50 5 126 51 32 122 5 43 130 51 53
127 26 17 -38 0 0 12 8 43 21 11 -16 126 55 36 127 57 12 123 11 1 131 58 27
128 33 36 -37 0 0 12 8 33 22 10 -17 128 2 49 129 4 38 124 17 41 133 7 11
129 42 46 -36 0 0 12 8 23 23 9 -18 129 11 50 130 13 58 125 25 50 134 18 14
130 53 56 -35 0 0 12 8 11 24 8 -20 130 22 47 131 25 21 126 35 35 135 31 48
132 7 14 -34 0 0 12 7 59 25 7 -21 131 35 49 132 38 56 127 47 3 136 48 5
133 22 52 -33 0 0 12 7 46 26 6 -23 132 51 8 133 54 55 129 0 23 138 7 21
134 41 3 -32 0 0 12 7 32 27 4 -24 134 8 54 135 13 30 130 15 44 139 29 53
136 1 59 -31 0 0 12 7 18 28 3 -25 135 29 22 136 34 56 131 33 17 140 56 2
137 25 58 -30 0 0 12 7 2 29 2 -27 136 52 47 137 59 31 132 53 14 142 26 12
138 53 19 -29 0 0 12 6 46 30 0 -29 138 19 28 139 27 34 134 15 49 144 0 55
140 24 25 -28 0 0 12 6 28 31 359 -30 139 49 47 140 59 29 135 41 16 145 40 49
141 59 44 -27 0 0 12 6 10 32 357 -32 141 24 10 142 35 47 137 9 56 147 26 41
143 39 50 -26 0 0 12 5 50 33 356 -34 143 3 9 144 17 4 138 42 9 149 19 35
145 25 25 -25 0 0 12 5 29 34 354 -35 144 47 24 146 4 4 140 18 22 151 20 54
147 17 24 -24 0 0 12 5 6 35 352 -37 146 37 46 147 57 47 141 59 6 153 32 35
149 16 58 -23 0 0 12 4 42 36 350 -39 148 35 20 149 59 30 143 45 1 155 57 32
151 25 44 -22 0 0 12 4 16 36 348 -41 150 41 35 152 11 0 145 36 55 158 40 18
Latitude Latitude Latitude Latitude
152 0 0 -21 44 50 12 4 9 36 347 -42 -21 25 0 -22 4 50 -19 0 29 -24 41 38
153 0 0 -21 19 4 12 3 56 37 346 -42 -20 59 24 -21 38 54 -18 35 55 -24 14 21
154 0 0 -20 54 19 12 3 44 37 345 -43 -20 34 47 -21 14 0 -18 12 19 -23 48 10
155 0 0 -20 30 33 12 3 32 37 344 -44 -20 11 10 -20 50 6 -17 49 39 -23 23 4
Uncertainty in time = +/- 18 secs
Prediction of 2011 Jan 27.0
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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