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Updated: 2012 Oct 07, 19:27 UT
Event Rank : 98
(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 Oct 26 UT, the 147 km diameter asteroid (804) Hispania will occult a 13.1 mag star in the constellation Capricornus for observers along a wide path across south-eastern Australia, running from Melbourne to Brisbane.
In the case of an occultation, the combined light of the asteroid and the star will drop by only 0.5 mag to 12.6 mag (the magnitude of the asteroid) for at most 7.2 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.
Occultation of 2UCAC 21436615 by 804 Hispania on 2012 Oct 26
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
140 10 17 -44 35 26 12 24 35 42 274 -27 138 53 40 -44 19 12 141 29 6 -44 50 53 137 58 19 -44 6 42 142 28 54 -45 1 46
140 53 9 -43 38 0 12 24 40 42 273 -28 139 37 10 -43 22 14 142 11 17 -43 52 58 138 42 17 -43 10 4 143 10 33 -44 3 28
141 36 32 -42 40 20 12 24 46 41 271 -29 140 21 8 -42 25 3 142 54 5 -42 54 48 139 26 39 -42 13 14 143 52 54 -43 4 57
142 20 33 -41 42 24 12 24 52 41 270 -30 141 5 38 -41 27 36 143 37 34 -41 56 22 140 11 31 -41 16 9 144 36 0 -42 6 8
143 5 14 -40 44 10 12 24 57 40 269 -31 141 50 45 -40 29 52 144 21 49 -40 57 37 140 56 56 -40 18 46 145 19 55 -41 7 0
143 50 41 -39 45 35 12 25 3 39 268 -32 142 36 33 -39 31 47 145 6 56 -39 58 30 141 42 59 -39 21 4 146 4 46 -40 7 29
144 36 59 -38 46 36 12 25 9 39 266 -34 143 23 7 -38 33 20 145 52 58 -38 58 58 142 29 45 -38 22 59 146 50 37 -39 7 32
145 24 14 -37 47 9 12 25 14 38 265 -35 144 10 33 -37 34 26 146 40 3 -37 58 58 143 17 19 -37 24 28 147 37 35 -38 7 5
146 12 32 -36 47 12 12 25 20 37 264 -36 144 58 57 -36 35 3 147 28 16 -36 58 25 144 5 48 -36 25 29 148 25 46 -37 6 4
147 2 1 -35 46 40 12 25 26 36 263 -37 145 48 25 -35 35 6 148 17 46 -35 57 15 144 55 17 -35 25 58 149 15 19 -36 4 26
147 52 47 -34 45 29 12 25 31 36 261 -38 146 39 6 -34 34 33 149 8 41 -34 55 25 145 45 54 -34 25 51 150 6 22 -35 2 4
148 45 1 -33 43 34 12 25 37 35 260 -40 147 31 7 -33 33 18 150 1 11 -33 52 48 146 37 48 -33 25 4 150 59 7 -33 58 54
149 38 53 -32 40 49 12 25 43 34 259 -41 148 24 38 -32 31 15 150 55 27 -32 49 18 147 31 6 -32 23 32 151 53 44 -32 54 48
150 34 34 -31 37 8 12 25 49 33 258 -42 149 19 51 -31 28 20 151 51 43 -31 44 48 148 26 1 -31 21 9 152 50 29 -31 49 40
151 32 20 -30 32 24 12 25 54 32 257 -44 150 16 58 -30 24 26 152 50 13 -30 39 10 149 22 43 -30 17 48 153 49 38 -30 43 19
152 32 26 -29 26 28 12 26 0 31 256 -45 151 16 15 -29 19 23 153 51 18 -29 32 14 150 21 28 -29 13 24 154 51 32 -29 35 35
153 35 14 -28 19 8 12 26 6 29 255 -46 152 17 59 -28 13 4 154 55 20 -28 23 48 151 22 31 -28 7 45 155 56 38 -28 26 15
154 41 8 -27 10 12 12 26 11 28 254 -48 153 22 34 -27 5 16 156 2 48 -27 13 36 152 26 14 -27 0 43 157 5 26 -27 15 2
155 50 41 -25 59 24 12 26 17 27 253 -49 154 30 27 -25 55 45 157 14 19 -26 1 22 153 33 2 -25 52 4 158 18 38 -26 1 36
157 4 32 -24 46 22 12 26 23 25 252 -51 155 42 11 -24 44 13 158 30 41 -24 46 38 154 43 26 -24 41 32 159 37 11 -24 45 27
Uncertainty in time = +/- 3 secs
Prediction of 2012 Oct 8.0
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