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Updated: 2010 OCT 19, 21:55 UT
Event Rank : 79
(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 14 UT, the 82 km diameter asteroid (559) Nanon will occult a 11.6 mag star in the constellation Taurus for observers along a path from Melbourne to Grafton passing near Canberra and Sydney.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.0 mag to 14.6 mag (the magnitude of the asteroid) for at most 8.1 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
139 41 14 -43 0 0 10 16 46 29 347 -5 140 38 59 138 44 9 141 59 53 137 26 25
140 32 45 -42 0 0 10 16 57 30 346 -6 141 30 13 139 35 59 142 50 43 138 18 43
141 25 16 -41 0 0 10 17 8 31 345 -7 142 22 30 140 28 46 143 42 44 139 11 52
142 18 51 -40 0 0 10 17 19 32 344 -9 143 15 55 141 22 32 144 35 58 140 5 55
143 13 34 -39 0 0 10 17 31 32 343 -10 144 10 33 142 17 21 145 30 31 141 0 56
144 9 30 -38 0 0 10 17 43 33 341 -11 145 6 28 143 13 19 146 26 27 141 56 59
145 6 43 -37 0 0 10 17 55 34 340 -12 146 3 45 144 10 30 147 23 53 142 54 10
146 5 19 -36 0 0 10 18 8 34 339 -13 147 2 30 145 9 0 148 22 54 143 52 34
147 5 25 -35 0 0 10 18 22 35 337 -14 148 2 49 146 8 54 149 23 37 144 52 15
148 7 7 -34 0 0 10 18 35 35 336 -16 149 4 51 147 10 19 150 26 11 145 53 21
149 10 34 -33 0 0 10 18 50 36 334 -17 150 8 44 148 13 23 151 30 45 146 55 59
150 15 54 -32 0 0 10 19 4 36 333 -18 151 14 36 149 18 14 152 37 29 148 0 16
151 23 17 -31 0 0 10 19 19 37 331 -20 152 22 40 150 25 2 153 46 35 149 6 20
152 32 56 -30 0 0 10 19 35 37 329 -21 153 33 6 151 33 57 154 58 17 150 14 22
153 45 3 -29 0 0 10 19 51 37 327 -22 154 46 11 152 45 13 156 12 52 151 24 34
154 59 55 -28 0 0 10 20 8 38 326 -24 156 2 11 153 59 2 157 30 40 152 37 7
156 17 48 -27 0 0 10 20 25 38 324 -26 157 21 27 155 15 42 158 52 3 153 52 17
157 39 7 -26 0 0 10 20 43 38 322 -27 158 44 22 156 35 33 160 17 31 155 10 22
159 4 17 -25 0 0 10 21 1 38 320 -29 160 11 28 157 59 0 161 47 40 156 31 41
160 33 50 -24 0 0 10 21 20 38 318 -31 161 43 20 159 26 30 163 23 13 157 56 41
Uncertainty in time = +/- 6 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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