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Updated: 2016 APR 26, 14:13 UT
Event Rank : 67
(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 2016 Jun 23 UT, the 66 km diameter asteroid (516) Amherstia will occult a 12.4 mag star in the constellation Norma for observers along a path across western South Australia and north-eastern Western Australia to near Derby.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.24 mag to 10.90 mag (the magnitude of the asteroid) for at most 11.0 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, astrometry for the asteroid kindly provided by Bill Owen, astrometry for the asteroid kindly provided by the IAU Minor Planet Center.
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 Alt
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 Crn
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
123 35 10 -14 0 0 13 27 50 60 178 -56 123 54 42 123 15 40 124 24 3 122 46 28 -0.16
123 55 17 -15 0 0 13 27 34 61 179 -56 124 14 55 123 35 40 124 44 25 123 6 18 -0.16
124 15 44 -16 0 0 13 27 17 62 179 -57 124 35 29 123 56 1 125 5 10 123 26 29 -0.16
124 36 34 -17 0 0 13 27 0 63 179 -57 124 56 26 124 16 43 125 26 18 123 47 0 -0.16
124 57 46 -18 0 0 13 26 42 64 180 -58 125 17 46 124 37 47 125 47 50 124 7 53 -0.15
125 19 22 -19 0 0 13 26 25 65 180 -58 125 39 31 124 59 15 126 9 47 124 29 8 -0.15
125 41 23 -20 0 0 13 26 8 66 181 -59 126 1 41 125 21 7 126 32 11 124 50 47 -0.15
126 3 50 -21 0 0 13 25 50 67 182 -59 126 24 17 125 43 25 126 55 1 125 12 50 -0.15
126 26 44 -22 0 0 13 25 32 68 182 -60 126 47 21 126 6 9 127 18 20 125 35 19 -0.15
126 50 6 -23 0 0 13 25 14 69 183 -60 127 10 54 126 29 20 127 42 9 125 58 15 -0.15
127 13 58 -24 0 0 13 24 56 70 184 -61 127 34 57 126 53 1 128 6 29 126 21 39 -0.15
127 38 21 -25 0 0 13 24 37 71 185 -61 127 59 31 127 17 12 128 31 22 126 45 33 -0.15
128 3 16 -26 0 0 13 24 19 72 186 -61 128 24 39 127 41 55 128 56 49 127 9 57 -0.15
128 28 45 -27 0 0 13 24 0 73 187 -62 128 50 22 128 7 11 129 22 52 127 34 54 -0.14
128 54 51 -28 0 0 13 23 42 74 188 -62 129 16 41 128 33 2 129 49 32 128 0 25 -0.14
129 21 34 -29 0 0 13 23 23 75 190 -62 129 43 39 128 59 31 130 16 52 128 26 31 -0.14
129 48 56 -30 0 0 13 23 4 76 191 -62 130 11 17 129 26 38 130 44 54 128 53 15 -0.14
130 17 0 -31 0 0 13 22 45 76 193 -63 130 39 38 129 54 26 131 13 40 129 20 39 -0.14
130 45 49 -32 0 0 13 22 26 77 196 -63 131 8 44 130 22 57 131 43 12 129 48 44 -0.14
131 15 24 -33 0 0 13 22 6 78 199 -63 131 38 37 130 52 13 132 13 33 130 17 34 -0.14
131 45 48 -34 0 0 13 21 47 79 202 -63 132 9 20 131 22 18 132 44 46 130 47 10 -0.14
Latitude Latitude Latitude Latitude
132 0 0 -34 27 28 13 21 38 79 203 -63 -33 41 56 -35 12 54 -32 33 25 -36 20 53 -0.14
133 0 0 -36 19 39 13 21 2 80 211 -63 -35 35 20 -37 3 53 -34 28 40 -38 10 5 -0.14
134 0 0 -38 5 50 13 20 27 81 221 -63 -37 22 41 -38 48 55 -36 17 47 -39 53 24 -0.14
135 0 0 -39 46 21 13 19 53 82 233 -63 -39 4 19 -40 28 19 -38 1 7 -41 31 11 -0.14
- 81 0 0 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. -42 19 1 ....
Uncertainty in time = +/- 9 secs
Prediction of 2016 Apr 26.0
Use these links for further information:
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