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Updated: 2010 OCT 19, 20:21 UT
Event Rank : 82
(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 Jan 22 UT, the 113 km diameter asteroid (481) Emita will occult a 13.4 mag star in the constellation Leo for observers along a wide path across New South Wales, western Queensland and Northern Territory.
In the case of an occultation, the combined light of the asteroid and the star will drop by only 0.4 mag to 12.5 mag (the magnitude of the asteroid) for at most 11.1 seconds. Note the nearly full moon nearby.
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
153 27 32 -38 0 0 17 19 30 23 339 -16 154 22 23 152 32 33 155 32 28 151 22 0
152 34 11 -37 0 0 17 19 36 24 340 -17 153 28 26 151 39 48 154 37 43 150 29 59
151 41 7 -36 0 0 17 19 43 25 340 -18 152 34 49 150 47 17 153 43 23 149 38 9
150 48 18 -35 0 0 17 19 49 26 341 -19 151 41 29 149 54 58 152 49 22 148 46 29
149 55 40 -34 0 0 17 19 56 27 342 -20 150 48 22 149 2 48 151 55 38 147 54 53
149 3 9 -33 0 0 17 20 3 29 342 -21 149 55 26 148 10 43 151 2 7 147 3 21
148 10 43 -32 0 0 17 20 11 30 343 -23 149 2 36 147 18 41 150 8 46 146 11 47
147 18 19 -31 0 0 17 20 18 31 344 -24 148 9 50 146 26 38 149 15 31 145 20 11
146 25 54 -30 0 0 17 20 26 32 344 -25 147 17 4 145 34 31 148 22 19 144 28 29
145 33 24 -29 0 0 17 20 35 33 345 -26 146 24 17 144 42 19 147 29 8 143 36 37
144 40 48 -28 0 0 17 20 43 34 346 -28 145 31 25 143 49 58 146 35 55 142 44 35
143 48 2 -27 0 0 17 20 52 35 346 -29 144 38 25 142 57 25 145 42 37 141 52 18
142 55 3 -26 0 0 17 21 1 37 347 -30 143 45 14 142 4 38 144 49 10 140 59 45
142 1 50 -25 0 0 17 21 11 38 348 -31 142 51 51 141 11 34 143 55 33 140 6 52
141 8 19 -24 0 0 17 21 21 39 349 -32 141 58 12 140 18 11 143 1 43 139 13 37
140 14 27 -23 0 0 17 21 31 40 350 -34 141 4 14 139 24 24 142 7 36 138 19 58
139 20 12 -22 0 0 17 21 41 41 350 -35 140 9 54 138 30 13 141 13 10 137 25 50
138 25 30 -21 0 0 17 21 52 42 351 -36 139 15 10 137 35 34 140 18 22 136 31 12
137 30 20 -20 0 0 17 22 3 43 352 -38 138 20 0 136 40 23 139 23 9 135 36 0
136 34 38 -19 0 0 17 22 14 44 353 -39 137 24 19 135 44 38 138 27 29 134 40 12
135 38 20 -18 0 0 17 22 25 46 354 -40 136 28 4 134 48 17 137 31 18 133 43 43
134 41 24 -17 0 0 17 22 37 47 355 -41 135 31 14 133 51 15 136 34 33 132 46 32
133 43 47 -16 0 0 17 22 49 48 356 -43 134 33 44 132 53 29 135 37 12 131 48 34
132 45 24 -15 0 0 17 23 2 49 358 -44 133 35 31 131 54 55 134 39 10 130 49 45
131 46 13 -14 0 0 17 23 15 50 359 -45 132 36 31 130 55 31 133 40 24 129 50 3
130 46 9 -13 0 0 17 23 28 51 0 -47 131 36 42 129 55 12 132 40 51 128 49 22
129 45 8 -12 0 0 17 23 41 52 1 -48 130 35 58 128 53 53 131 40 27 127 47 38
128 43 6 -11 0 0 17 23 55 53 3 -50 129 34 15 127 51 30 130 39 7 126 44 47
127 39 58 -10 0 0 17 24 9 54 4 -51 128 31 29 126 47 59 129 36 48 125 40 44
Uncertainty in time = +/- 8 secs
Prediction of 2010 Dec 23.0
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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