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Updated: 2009 SEP 07, 01:12 UT
Event Rank : 8
(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 2009 Oct 12 UT, the 11 km diameter asteroid (11151) Oodaigahara will occult a 8.0 mag star in the constellation Andromeda for observers along a narrow, significant uncertainty path across Australia, running from Mackay to Eucla.
In the case of an occultation, the combined light of the asteroid and the star will drop by 7.6 mag to 15.6 mag (the magnitude of the asteroid) for at most 1.1 seconds.
This update is based on historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: .
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
123 52 37 -37 0 0 15 59 15 26 344 -45 123 43 22 124 1 53 121 19 8 126 34 28
124 53 43 -36 0 0 15 59 3 27 343 -46 124 44 24 125 3 4 122 19 9 127 37 4
125 57 26 -35 0 0 15 58 51 28 342 -47 125 48 1 126 6 52 123 21 28 128 42 41
127 3 57 -34 0 0 15 58 38 28 340 -47 126 54 25 127 13 31 124 26 15 129 51 33
128 13 30 -33 0 0 15 58 24 29 339 -48 128 3 49 128 23 12 125 33 41 131 3 56
129 26 20 -32 0 0 15 58 10 29 338 -49 129 16 29 129 36 13 126 43 57 132 20 13
130 42 47 -31 0 0 15 57 55 30 336 -49 130 32 44 130 52 53 127 57 19 133 40 48
132 3 14 -30 0 0 15 57 39 30 335 -50 131 52 56 132 13 35 129 14 4 135 6 14
133 28 9 -29 0 0 15 57 23 31 333 -50 133 17 33 133 38 48 130 34 34 136 37 12
134 58 8 -28 0 0 15 57 6 31 332 -51 134 47 11 135 9 9 131 59 14 138 14 35
136 33 57 -27 0 0 15 56 47 31 330 -51 136 22 33 136 45 25 133 28 37 139 59 34
138 16 35 -26 0 0 15 56 28 31 328 -51 138 4 39 138 28 36 135 3 23 141 53 47
140 7 23 -25 0 0 15 56 8 31 326 -51 139 54 45 140 20 7 136 44 23 143 59 39
142 8 15 -24 0 0 15 55 46 31 324 -50 141 54 43 142 21 54 138 32 46 146 20 53
143 0 0 -23 36 0 15 55 36 31 323 -50 -23 29 38 -23 42 23 -21 50 36 -25 27 39
144 0 0 -23 9 25 15 55 26 31 322 -50 -23 3 7 -23 15 44 -21 25 3 -24 59 50
145 0 0 -22 44 8 15 55 15 31 322 -50 -22 37 54 -22 50 23 -21 0 44 -24 33 26
146 0 0 -22 20 10 15 55 5 30 321 -49 -22 13 59 -22 26 21 -20 37 39 -24 8 24
147 0 0 -21 57 28 15 54 55 30 320 -49 -21 51 20 -22 3 36 -20 15 47 -23 44 43
148 0 0 -21 36 2 15 54 45 30 319 -49 -21 29 57 -21 42 7 -19 55 7 -23 22 23
149 0 0 -21 15 50 15 54 35 30 318 -48 -21 9 48 -21 21 53 -19 35 39 -23 1 21
150 0 0 -20 56 53 15 54 25 29 317 -48 -20 50 54 -21 2 54 -19 17 22 -22 41 38
151 0 0 -20 39 10 15 54 15 29 316 -47 -20 33 13 -20 45 8 -19 0 15 -22 23 12
152 0 0 -20 22 39 15 54 6 28 316 -47 -20 16 44 -20 28 35 -18 44 17 -22 6 2
153 0 0 -20 7 20 15 53 57 28 315 -46 -20 1 27 -20 13 14 -18 29 29 -21 50 8
154 0 0 -19 53 13 15 53 48 27 314 -45 -19 47 22 -19 59 6 -18 15 50 -21 35 29
155 0 0 -19 40 18 15 53 39 27 313 -45 -19 34 28 -19 46 9 -18 3 19 -21 22 5
Uncertainty in time = +/- 15 secs
Prediction of 2009 Sep 7.0
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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