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Updated: 2008 OCT 30, 23:22 UT
Event Rank : 62
(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 Dec 03 UT, the 50 km diameter asteroid (312) Pierretta will occult a 11.6 mag star in the constellation Auriga for observers along a path beginning over the New South Wales - Victoria border area passing near Orbost, Albury and Wagga Wagga. Moving west the path passes near Broken Hill and then through central South Australia passing near Coober Pedy. Then into central Western Australia passing just south of Newman before ending near Coral Bay and Carnarvon.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 13.6 mag (the magnitude of the asteroid) for at most 3.4 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
153 9 55 -41 0 0 16 47 3 7 332 -13 153 56 12 152 22 56 155 25 54 150 47 38
152 2 0 -40 0 0 16 47 6 8 333 -14 152 48 38 151 14 36 154 18 57 149 38 24
150 51 17 -39 0 0 16 47 9 10 334 -16 151 38 24 150 3 22 153 9 32 148 25 58
149 37 32 -38 0 0 16 47 12 11 334 -17 150 25 15 148 48 58 151 57 25 147 10 5
148 20 29 -37 0 0 16 47 17 12 335 -19 149 8 56 147 31 6 150 42 24 145 50 23
146 59 47 -36 0 0 16 47 22 14 336 -20 147 49 9 146 9 25 149 24 12 144 26 27
145 35 1 -35 0 0 16 47 27 15 337 -21 146 25 30 144 43 27 148 2 29 142 57 44
144 5 42 -34 0 0 16 47 34 16 338 -23 144 57 31 143 12 39 146 36 52 141 23 35
142 31 12 -33 0 0 16 47 41 18 339 -25 143 24 40 141 36 21 145 6 52 139 43 8
140 50 43 -32 0 0 16 47 49 19 341 -26 141 46 12 139 53 38 143 31 52 137 55 15
139 3 12 -31 0 0 16 47 58 21 342 -28 140 1 11 138 3 20 141 51 9 135 58 22
137 7 14 -30 0 0 16 48 8 22 343 -30 138 8 24 136 3 48 140 3 42 133 50 15
135 0 50 -29 0 0 16 48 20 24 345 -31 136 6 6 133 52 41 138 8 14 131 27 28
Latitude Latitude Latitude Latitude
134 0 0 -28 33 5 16 48 26 24 346 -32 -28 3 28 -29 3 11 -27 6 11 -30 4 21
133 0 0 -28 7 46 16 48 32 25 347 -33 -27 38 27 -28 37 34 -26 41 42 -29 38 4
132 0 0 -27 43 38 16 48 38 25 347 -34 -27 14 36 -28 13 9 -26 18 21 -29 13 3
131 0 0 -27 20 42 16 48 44 26 348 -35 -26 51 55 -27 49 56 -25 56 9 -28 49 16
130 0 0 -26 58 56 16 48 51 26 349 -35 -26 30 23 -27 27 55 -25 35 4 -28 26 43
129 0 0 -26 38 20 16 48 57 27 350 -36 -26 10 0 -27 7 5 -25 15 6 -28 5 22
128 0 0 -26 18 52 16 49 3 27 351 -37 -25 50 45 -26 47 24 -24 56 14 -27 45 14
127 0 0 -26 0 33 16 49 10 28 352 -37 -25 32 37 -26 28 53 -24 38 28 -27 26 17
126 0 0 -25 43 21 16 49 16 28 352 -38 -25 15 36 -26 11 30 -24 21 47 -27 8 30
125 0 0 -25 27 16 16 49 23 29 353 -39 -24 59 42 -25 55 15 -24 6 11 -26 51 52
124 0 0 -25 12 18 16 49 29 29 354 -39 -24 44 52 -25 40 7 -23 51 39 -26 36 24
123 0 0 -24 58 26 16 49 36 29 355 -40 -24 31 9 -25 26 6 -23 38 11 -26 22 4
122 0 0 -24 45 39 16 49 43 30 356 -40 -24 18 30 -25 13 11 -23 25 46 -26 8 52
121 0 0 -24 33 57 16 49 49 30 357 -41 -24 6 55 -25 1 22 -23 14 25 -25 56 48
120 0 0 -24 23 20 16 49 56 30 358 -41 -23 56 24 -24 50 38 -23 4 6 -25 45 51
119 0 0 -24 13 48 16 50 3 30 359 -42 -23 46 57 -24 41 0 -22 54 50 -25 36 0
118 0 0 -24 5 19 16 50 10 30 360 -42 -23 38 34 -24 32 26 -22 46 36 -25 27 16
117 0 0 -23 57 55 16 50 16 30 1 -42 -23 31 14 -24 24 57 -22 39 23 -25 19 37
116 0 0 -23 51 34 16 50 23 31 1 -43 -23 24 57 -24 18 33 -22 33 13 -25 13 4
115 0 0 -23 46 17 16 50 30 31 2 -43 -23 19 42 -24 13 12 -22 28 4 -25 7 37
114 0 0 -23 42 3 16 50 37 31 3 -43 -23 15 31 -24 8 56 -22 23 57 -25 3 15
113 0 0 -23 38 52 16 50 44 31 4 -44 -23 12 21 -24 5 43 -22 20 51 -24 59 58
112 0 0 -23 36 44 16 50 50 31 5 -44 -23 10 15 -24 3 34 -22 18 47 -24 57 47
111 0 0 -23 35 39 16 50 57 31 6 -44 -23 9 10 -24 2 28 -22 17 44 -24 56 40
110 0 0 -23 35 37 16 51 4 30 7 -44 -23 9 8 -24 2 26 -22 17 42 -24 56 39
109 0 0 -23 36 38 16 51 11 30 8 -44 -23 10 9 -24 3 28 -22 18 41 -24 57 42
108 0 0 -23 38 42 16 51 18 30 9 -44 -23 12 12 -24 5 34 -22 20 41 -24 59 50
Uncertainty in time = +/- 3 secs
[Prediction of 2008 Oct 30.0]
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[Observing Details]
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