Updated: 2012 JAN 26, 13:28 UT
Event Rank : 90
(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 2012 Mar 10 UT, the 57 km diameter asteroid (585) Bilkis will occult a 9.6 mag star in the constellation Leo for observers along a path across Australia from Hobart across central Tasmania, central Victoria including Melbourne and Bendigo, western New South Wales, and The Northern Territory to northern Western Australia near Wyndham.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.6 mag to 13.2 mag (the magnitude of the asteroid) for at most 9.0 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, 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 148 43 53 -47 0 0 10 58 8 32 23 -23 149 16 28 148 11 9 149 50 12 147 36 57 148 20 56 -46 0 0 10 58 21 32 24 -24 148 53 2 147 48 41 149 26 16 147 14 59 147 57 6 -45 0 0 10 58 35 33 24 -24 148 28 45 147 25 19 149 1 31 146 52 5 147 32 25 -44 0 0 10 58 48 34 25 -24 148 3 39 147 1 3 148 35 59 146 28 16 147 6 54 -43 0 0 10 59 2 35 26 -25 147 37 44 146 35 56 148 9 40 146 3 33 146 40 33 -42 0 0 10 59 17 36 26 -25 147 11 2 146 9 57 147 42 34 145 37 58 146 13 24 -41 0 0 10 59 31 36 27 -25 146 43 32 145 43 8 147 14 43 145 11 30 145 45 26 -40 0 0 10 59 46 37 28 -25 146 15 15 145 15 29 146 46 7 144 44 11 145 16 40 -39 0 0 11 0 2 38 29 -26 145 46 11 144 47 0 146 16 45 144 16 0 144 47 6 -38 0 0 11 0 17 39 30 -26 145 16 21 144 17 42 145 46 38 143 46 59 144 16 43 -37 0 0 11 0 33 39 31 -26 144 45 44 143 47 35 145 15 45 143 17 7 143 45 33 -36 0 0 11 0 49 40 32 -26 144 14 20 143 16 38 144 44 7 142 46 25 143 13 35 -35 0 0 11 1 6 41 32 -26 143 42 9 142 44 52 144 11 44 142 14 51 142 40 48 -34 0 0 11 1 23 41 34 -26 143 9 11 142 12 16 143 38 34 141 42 27 142 7 11 -33 0 0 11 1 40 42 35 -26 142 35 25 141 38 50 143 4 37 141 9 11 141 32 45 -32 0 0 11 1 57 42 36 -26 142 0 50 141 4 32 142 29 53 140 35 3 140 57 29 -31 0 0 11 2 15 43 37 -26 141 25 26 140 29 23 141 54 21 140 0 1 140 21 21 -30 0 0 11 2 33 43 38 -26 140 49 11 139 53 22 141 17 59 139 24 6 139 44 20 -29 0 0 11 2 51 44 39 -26 140 12 5 139 16 27 140 40 48 138 47 17 139 6 27 -28 0 0 11 3 10 44 40 -26 139 34 7 138 38 37 140 2 45 138 9 31 138 27 38 -27 0 0 11 3 29 45 42 -26 138 55 16 137 59 52 139 23 50 137 30 49 137 47 53 -26 0 0 11 3 48 45 43 -26 138 15 29 137 20 8 138 44 1 136 51 7 137 7 10 -25 0 0 11 4 7 46 44 -26 137 34 45 136 39 26 138 3 16 136 10 26 136 25 28 -24 0 0 11 4 27 46 46 -25 136 53 3 135 57 43 137 21 35 135 28 42 135 42 44 -23 0 0 11 4 47 46 47 -25 136 10 21 135 14 58 136 38 53 134 45 54 134 58 56 -22 0 0 11 5 7 46 49 -25 135 26 36 134 31 7 135 55 11 134 1 59 134 14 2 -21 0 0 11 5 27 46 50 -24 134 41 46 133 46 8 135 10 25 133 16 56 133 27 59 -20 0 0 11 5 48 47 52 -24 133 55 48 133 0 0 134 24 33 132 30 41 132 40 45 -19 0 0 11 6 9 47 53 -24 133 8 41 132 12 38 133 37 32 131 43 11 131 52 15 -18 0 0 11 6 30 47 55 -23 132 20 19 131 23 59 132 49 19 130 54 23 131 2 27 -17 0 0 11 6 51 47 56 -23 131 30 41 130 34 1 131 59 51 130 4 14 130 11 16 -16 0 0 11 7 13 47 58 -22 130 39 42 129 42 38 131 9 4 129 12 38 129 18 39 -15 0 0 11 7 35 47 59 -22 129 47 18 128 49 47 130 16 53 128 19 31 128 24 30 -14 0 0 11 7 57 46 61 -21 128 53 25 127 55 22 129 23 15 127 24 49 127 28 44 -13 0 0 11 8 19 46 62 -20 127 57 57 126 59 18 128 28 4 126 28 26 126 31 16 -12 0 0 11 8 42 46 64 -20 127 0 48 126 1 29 127 31 15 125 30 14 125 31 57 -11 0 0 11 9 5 45 65 -19 126 1 52 125 1 47 126 32 41 124 30 8 124 30 42 -10 0 0 11 9 28 45 67 -18 125 1 1 124 0 6 125 32 16 123 27 58 123 27 21 - 9 0 0 11 9 51 45 68 -17 123 58 8 122 56 15 124 29 51 122 23 35 122 21 44 - 8 0 0 11 10 14 44 69 -17 122 53 3 121 50 5 123 25 17 121 16 50 Uncertainty in time = +/- 5 secs Prediction of 2012 Jan 26.0
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