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Updated: 2011 NOV 10, 22:00 UT
Event Rank : 82
(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 2011 Dec 20 UT, the 61 km diameter asteroid (679) Pax will occult a 10.4 mag star in the constellation Piscis Austrinus for observers along a path across Australia from Streaky Bay across South Australia and central Queensland to near Townsville at decreasing elevation.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.7 mag to 13.0 mag (the magnitude of the asteroid) for at most 1.8 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
129 37 31 -37 52 41 13 13 32 30 253 -22 129 1 45 -37 51 34 130 13 46 -37 53 30 128 16 40 -37 49 44 131 0 57 -37 54 5
130 38 50 -36 44 39 13 13 35 29 252 -24 130 2 47 -36 44 3 131 15 25 -36 44 56 129 17 23 -36 42 50 132 3 2 -36 44 49
131 42 46 -35 34 54 13 13 38 28 251 -25 131 6 19 -35 34 52 132 19 46 -35 34 35 130 20 27 -35 34 21 133 8 0 -35 33 40
132 49 43 -34 23 9 13 13 42 27 250 -26 132 12 44 -34 23 45 133 27 19 -34 22 9 131 26 15 -34 24 2 134 16 21 -34 20 19
134 0 16 -33 9 2 13 13 45 26 249 -28 133 22 35 -33 10 24 134 38 37 -33 7 16 132 35 16 -33 11 34 135 28 44 -33 4 21
135 15 7 -31 52 8 13 13 48 24 248 -30 134 36 31 -31 54 22 135 54 29 -31 49 26 133 48 7 -31 56 35 136 46 2 -31 45 15
136 35 16 -30 31 49 13 13 52 23 247 -31 135 55 25 -30 35 6 137 15 58 -30 28 0 135 5 36 -30 38 34 138 9 25 -30 22 15
138 2 2 -29 7 17 13 13 55 21 246 -33 137 20 33 -29 11 52 138 44 33 -29 2 3 136 28 49 -29 16 52 139 40 36 -28 54 19
139 37 26 -27 37 16 13 13 59 19 245 -35 138 53 40 -27 43 32 140 22 30 -27 30 11 137 59 21 -27 50 29 141 22 16 -27 19 48
141 24 39 -25 59 51 13 14 2 17 244 -37 140 37 34 -26 8 26 142 13 29 -25 50 10 139 39 32 -26 18 0 143 18 56 -25 35 57
143 29 19 -24 11 34 13 14 5 14 243 -40 142 36 59 -24 23 38 144 24 20 -23 57 51 141 33 16 -24 37 3 145 39 30 -23 37 19
146 3 31 -22 5 8 13 14 9 11 242 -42 145 1 27 -22 23 23 147 10 51 -21 43 38 143 47 51 -22 43 9 148 47 52 -21 9 29
149 46 31 -19 16 50 13 14 12 7 240 -46 148 17 19 -19 51 46 151 39 40 -18 27 25 146 40 46 -20 25 47 ... .. .. .. .. ..
Uncertainty in time = +/- 1 secs
Prediction of 2011 Nov 11.0
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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