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Updated: 2008 SEP 11, 17:09 UT
Event Rank : 28
(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 2008 Oct 13 UT, the 24 km diameter asteroid (1766) Slipher will occult a 10.1 mag star in the constellation Taurus for observers along a narrow path across Queensland and South Australia, beginning near Ayr and leaving at Eyre Peninsula.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.8 mag to 15.9 mag (the magnitude of the asteroid) for at most 5.3 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
132 41 0 -37 0 0 18 2 54 37 358 -27 132 28 50 132 53 10 131 31 6 133 51 19
133 29 27 -36 0 0 18 2 33 38 357 -27 133 17 23 133 41 32 132 20 8 134 39 14
134 18 12 -35 0 0 18 2 12 39 356 -27 134 6 13 134 30 12 133 9 23 135 27 29
135 7 16 -34 0 0 18 1 50 40 355 -27 134 55 22 135 19 11 133 58 55 136 16 5
135 56 41 -33 0 0 18 1 27 41 354 -27 135 44 52 136 8 32 134 48 46 137 5 6
136 46 30 -32 0 0 18 1 4 42 353 -27 136 34 44 136 58 17 135 38 57 137 54 33
137 36 44 -31 0 0 18 0 40 42 352 -27 137 25 2 137 48 27 136 29 31 138 44 28
138 27 26 -30 0 0 18 0 15 43 351 -27 138 15 46 138 39 6 137 20 30 139 34 53
139 18 37 -29 0 0 17 59 51 44 350 -27 139 7 0 139 30 15 138 11 56 140 25 50
140 10 21 -28 0 0 17 59 25 45 348 -27 139 58 46 140 21 56 139 3 52 141 17 22
141 2 38 -27 0 0 17 58 59 46 347 -27 140 51 5 141 14 12 139 56 20 142 9 31
141 55 32 -26 0 0 17 58 33 47 346 -27 141 44 0 142 7 5 140 49 21 143 2 18
142 49 5 -25 0 0 17 58 6 47 345 -26 142 37 34 143 0 37 141 42 59 143 55 48
143 43 19 -24 0 0 17 57 38 48 343 -26 143 31 49 143 54 51 142 37 15 144 50 1
144 38 18 -23 0 0 17 57 10 49 342 -26 144 26 47 144 49 50 143 32 13 145 45 0
145 34 2 -22 0 0 17 56 42 50 340 -26 145 22 31 145 45 35 144 27 55 146 40 50
146 30 37 -21 0 0 17 56 13 50 339 -25 146 19 4 146 42 11 145 24 23 147 37 31
147 28 4 -20 0 0 17 55 43 51 337 -25 147 16 29 147 39 39 146 21 41 148 35 8
148 26 26 -19 0 0 17 55 13 52 335 -24 148 14 50 148 38 4 147 19 53 149 33 44
149 25 48 -18 0 0 17 54 43 52 334 -24 149 14 9 149 37 28 148 19 0 150 33 21
Uncertainty in time = +/- 16 secs
[Prediction of 2008 Sep 11.0]
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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