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Updated: 2012 JUN 21, 02:39 UT
Event Rank : 65
(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 Aug 09 UT, the 70 km diameter asteroid (1264) Letaba will occult a 11.8 mag star in the constellation Triangulum for observers along a south-to-north path across New Zealand centred from near Te Anau to near Auckland.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.5 mag to 15.2 mag (the magnitude of the asteroid) for at most 6.5 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, 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
161 34 31 -53 0 0 17 11 51 5 15 -31 162 36 41 160 33 6 164 34 32 ... .. ..
162 17 11 -52 0 0 17 11 53 6 14 -31 163 18 27 161 16 40 165 14 37 159 25 58
163 1 5 -51 0 0 17 11 55 8 14 -31 164 1 33 162 1 22 165 56 13 160 12 11
163 46 14 -50 0 0 17 11 58 9 13 -31 164 45 59 162 47 14 166 39 20 160 59 24
164 32 38 -49 0 0 17 12 2 10 13 -30 165 31 45 163 34 17 167 23 57 161 47 38
165 20 19 -48 0 0 17 12 5 11 12 -30 166 18 54 164 22 32 168 10 7 162 36 56
166 9 20 -47 0 0 17 12 10 12 11 -30 167 7 27 165 12 0 168 57 50 163 27 19
166 59 41 -46 0 0 17 12 14 13 10 -29 167 57 25 166 2 45 169 47 9 164 18 50
167 51 26 -45 0 0 17 12 20 14 10 -29 168 48 53 166 54 49 170 38 8 165 11 31
168 44 39 -44 0 0 17 12 25 15 9 -28 169 41 53 167 48 15 171 30 48 166 5 26
169 39 22 -43 0 0 17 12 31 16 8 -28 170 36 30 168 43 8 172 25 16 167 0 39
170 35 42 -42 0 0 17 12 38 17 7 -27 171 32 47 169 39 31 173 21 36 167 57 13
171 33 43 -41 0 0 17 12 45 18 6 -26 172 30 52 170 37 30 174 19 54 168 55 14
172 33 32 -40 0 0 17 12 53 19 6 -26 173 30 51 171 37 12 175 20 18 169 54 48
173 35 15 -39 0 0 17 13 2 21 5 -25 174 32 50 172 38 42 176 22 56 170 55 59
174 39 2 -38 0 0 17 13 11 22 4 -24 175 37 0 173 42 8 177 27 59 171 58 56
175 45 1 -37 0 0 17 13 20 23 3 -23 176 43 30 174 47 40 178 35 39 173 3 47
176 53 24 -36 0 0 17 13 31 24 2 -22 177 52 33 175 55 28 179 46 10 174 10 40
178 4 24 -35 0 0 17 13 42 25 0 -21 179 4 23 177 5 45 -179 0 11 175 19 47
179 18 18 -34 0 0 17 13 53 26 359 -20 -179 40 43 178 18 44 -177 43 3 176 31 20
-179 24 37 -33 0 0 17 14 6 27 358 -18 -178 22 24 179 34 42 -176 22 1 177 45 33
-178 3 58 -32 0 0 17 14 19 28 356 -17 -177 0 15 -179 5 59 -174 56 33 179 2 44
-176 39 17 -31 0 0 17 14 34 29 355 -16 -175 33 44 -177 42 55 -173 25 59 -179 36 46
-175 9 59 -30 0 0 17 14 49 29 353 -14 -174 2 13 -176 15 35 -171 49 28 -178 12 34
-173 35 21 -29 0 0 17 15 6 30 352 -13 -172 24 51 -174 43 22 -170 5 51 -176 44 8
Uncertainty in time = +/- 6 secs
Prediction of 2012 Jun 21.0
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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