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Updated: 2007 OCT 13, 23:06 UT
Event Rank : 29
(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 2007 Nov 12 UT, the 27 km diameter asteroid (992) Swasey will occult a 9.7 mag star in the constellation Monoceros for observers along a path across central Australia in morning twilight.
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.2 mag to 15.9 mag (the magnitude of the asteroid) for at most 4.1 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
123 18 30 -38 0 0 19 47 35 39 344 -8 123 5 54 123 31 8 122 8 40 124 28 54
123 49 47 -37 0 0 19 47 21 40 343 -8 123 37 18 124 2 17 122 40 37 124 59 30
124 21 31 -36 0 0 19 47 7 41 342 -8 124 9 9 124 33 54 123 12 59 125 30 36
124 53 43 -35 0 0 19 46 52 41 341 -9 124 41 27 125 6 0 123 45 45 126 2 13
125 26 23 -34 0 0 19 46 37 42 340 -9 125 14 13 125 38 34 124 18 58 126 34 21
125 59 33 -33 0 0 19 46 22 43 339 -9 125 47 28 126 11 38 124 52 38 127 7 1
126 33 12 -32 0 0 19 46 7 44 338 -9 126 21 13 126 45 13 125 26 44 127 40 14
127 7 23 -31 0 0 19 45 51 45 337 -9 126 55 27 127 19 19 126 1 20 128 13 59
127 42 5 -30 0 0 19 45 35 45 336 -9 127 30 14 127 53 57 126 36 25 128 48 19
128 17 19 -29 0 0 19 45 19 46 335 -9 128 5 32 128 29 8 127 12 0 129 23 14
128 53 8 -28 0 0 19 45 3 47 334 -9 128 41 23 129 4 53 127 48 6 129 58 44
129 29 31 -27 0 0 19 44 46 47 333 -9 129 17 49 129 41 13 128 24 45 130 34 52
130 6 29 -26 0 0 19 44 29 48 332 -9 129 54 51 130 18 10 129 1 58 131 11 37
130 44 5 -25 0 0 19 44 12 49 330 -9 130 32 28 130 55 43 129 39 45 131 49 2
131 22 19 -24 0 0 19 43 54 49 329 -9 131 10 44 131 33 56 130 18 9 132 27 8
132 1 13 -23 0 0 19 43 36 50 328 -9 131 49 39 132 12 48 130 57 10 133 5 55
132 40 48 -22 0 0 19 43 18 50 326 -9 132 29 15 132 52 22 131 36 50 133 45 25
133 21 5 -21 0 0 19 43 0 51 325 -9 133 9 32 133 32 39 132 17 10 134 25 41
134 2 7 -20 0 0 19 42 42 51 323 -9 133 50 34 134 13 41 132 58 12 135 6 43
134 43 54 -19 0 0 19 42 23 52 322 -8 134 32 21 134 55 29 133 39 57 135 48 33
135 26 30 -18 0 0 19 42 4 52 320 -8 135 14 56 135 38 5 134 22 29 136 31 13
136 9 55 -17 0 0 19 41 45 53 319 -8 135 58 20 136 21 31 135 5 48 137 14 46
136 54 12 -16 0 0 19 41 25 53 317 -8 136 42 35 137 5 50 135 49 56 137 59 14
137 39 24 -15 0 0 19 41 6 53 315 -7 137 27 45 137 51 4 136 34 56 138 44 39
138 25 32 -14 0 0 19 40 46 53 313 -7 138 13 50 138 37 15 137 20 50 139 31 3
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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