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Updated: 2007 AUG 02, 12:42 UT
Event Rank : 8
(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 Oct 26 UT, the 13 km diameter asteroid (3509) Sanshui will occult a 9.6 mag star in the constellation Pisces for observers along a narrow path of large uncertainty crossing north-western NT, near Darwin during late evening twilight.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.7 mag to 15.3 mag (the magnitude of the asteroid) for at most 1.8 seconds.
This update is based on 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
131 57 10 -10 56 45 9 59 52 49 64 -13 132 1 36 -10 56 37 131 52 44 -10 56 54 133 18 4 -10 54 21 130 34 47 -10 59 30
131 35 20 -12 13 40 10 0 10 49 63 -12 131 39 48 -12 13 31 131 30 51 -12 13 49 132 56 56 -12 11 11 130 12 11 -12 16 31
131 11 51 -13 31 18 10 0 29 48 62 -12 131 16 23 -13 31 9 131 7 20 -13 31 27 132 34 16 -13 28 42 129 47 50 -13 34 15
130 46 37 -14 49 42 10 0 47 47 61 -11 130 51 11 -14 49 33 130 42 3 -14 49 51 132 9 56 -14 47 0 129 21 38 -14 52 47
130 19 29 -16 8 57 10 1 5 46 60 -10 130 24 7 -16 8 47 130 14 51 -16 9 7 131 43 48 -16 6 7 128 53 25 -16 12 10
129 50 17 -17 29 7 10 1 24 45 59 -9 129 54 59 -17 28 57 129 45 36 -17 29 17 131 15 44 -17 26 9 128 23 0 -17 32 30
129 18 51 -18 50 18 10 1 42 44 58 -9 129 23 37 -18 50 7 129 14 5 -18 50 29 130 45 34 -18 47 10 127 50 11 -18 53 51
128 44 56 -20 12 35 10 2 0 43 58 -8 128 49 47 -20 12 23 128 40 6 -20 12 46 130 13 5 -20 9 16 127 14 44 -20 16 20
128 8 18 -21 36 4 10 2 19 41 57 -7 128 13 14 -21 35 52 128 3 22 -21 36 16 129 38 2 -21 32 33 126 36 21 -21 40 3
127 28 38 -23 0 53 10 2 37 40 57 -6 127 33 40 -23 0 40 127 23 35 -23 1 6 129 0 10 -22 57 8 125 54 43 -23 5 7
126 45 33 -24 27 9 10 2 55 39 56 -5 126 50 42 -24 26 55 126 40 23 -24 27 23 128 19 8 -24 23 8 125 9 24 -24 31 41
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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