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Updated: 2012 JUL 07, 22:55 UT
Event Rank : 9
(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 07 UT, the 15 km diameter asteroid (6383) Tokushima will occult a 10.1 mag star in the constellation Sagittarius for observers along a quite narrow path passing near Sydney and Melbourne, but this is a low altitude event.
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.3 mag to 16.4 mag (the magnitude of the asteroid) for at most 4.2 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 Limit1 Path Limit2 Error Limit1 Error Limit2
E. Longitude Latitude U.T. Alt Az Alt
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
158 26 49 -28 48 57 16 59 31 5 240 -41 159 6 8 -28 31 14 157 51 20 -29 4 27 ... .. .. .. .. .. 152 3 24 -31 13 16
155 40 22 -30 51 26 16 59 55 8 241 -43 156 6 17 -30 41 30 155 15 29 -31 0 45 ... .. .. .. .. .. 150 26 58 -32 34 17
153 41 4 -32 26 51 17 0 18 11 243 -44 154 2 29 -32 19 37 153 20 13 -32 33 46 161 33 36 -29 11 6 149 2 44 -33 48 19
152 3 38 -33 49 45 17 0 42 12 244 -45 152 22 37 -33 43 59 151 44 59 -33 55 19 157 57 45 -31 43 43 147 47 11 -34 57 26
150 39 34 -35 5 2 17 1 6 14 244 -46 150 57 2 -35 0 14 150 22 21 -35 9 41 155 47 0 -33 27 17 146 38 12 -36 2 51
149 24 48 -36 15 3 17 1 30 15 245 -47 149 41 13 -36 10 55 149 8 35 -36 19 3 154 5 1 -34 54 19 145 34 26 -37 5 20
148 17 2 -37 21 8 17 1 53 16 246 -47 148 32 41 -37 17 32 148 1 32 -37 24 38 152 39 8 -36 12 10 144 34 57 -38 5 27
147 14 45 -38 24 11 17 2 17 18 247 -48 147 29 50 -38 21 0 146 59 49 -38 27 17 151 23 56 -37 23 58 143 39 3 -39 3 36
146 16 59 -39 24 46 17 2 41 19 248 -48 146 31 37 -39 21 55 146 2 28 -39 27 32 150 16 35 -38 31 24 142 46 16 -40 0 6
145 23 0 -40 23 20 17 3 5 19 248 -48 145 37 17 -40 20 46 145 8 48 -40 25 50 149 15 18 -39 35 29 141 56 11 -40 55 9
144 32 16 -41 20 11 17 3 29 20 249 -48 144 46 17 -41 17 51 144 18 20 -41 22 27 148 18 56 -40 36 55 141 8 29 -41 48 59
143 44 22 -42 15 35 17 3 52 21 250 -48 143 58 11 -42 13 27 143 30 38 -42 17 39 147 26 41 -41 36 11 140 22 56 -42 41 44
142 59 1 -43 9 43 17 4 16 22 251 -48 143 12 40 -43 7 46 142 45 26 -43 11 36 146 37 58 -42 33 39 139 39 20 -43 33 31
142 15 56 -44 2 45 17 4 40 23 251 -48 142 29 28 -44 0 58 142 2 28 -44 4 29 145 52 20 -43 29 34 138 57 31 -44 24 28
141 34 56 -44 54 50 17 5 4 23 252 -48 141 48 23 -44 53 11 141 21 33 -44 56 25 145 9 27 -44 24 10 138 17 21 -45 14 40
Uncertainty in time = +/- 37 secs
Prediction of 2012 Jul 8.0
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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