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Updated: 2008 DEC 03, 21:40 UT
Event Rank : 67
(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 2009 Jan 10 UT, the 77 km diameter asteroid (1118) Hanskya will occult a 9.6 mag star in the constellation Triangulum for observers along a path across central Western Australia, beginning at Port Hedland and leaving near the town of Eyre.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.5 mag to 15.1 mag (the magnitude of the asteroid) for at most 10.4 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
131 27 16 -37 0 0 14 15 3 4 317 -29 130 51 18 132 3 32 129 48 43 133 8 10
130 21 23 -36 0 0 14 15 2 5 318 -30 129 46 25 130 56 39 128 45 30 131 59 24
129 18 34 -35 0 0 14 15 0 6 318 -31 128 44 30 129 52 54 127 45 8 130 53 57
128 18 34 -34 0 0 14 14 58 8 319 -31 127 45 20 128 52 2 126 47 23 129 51 32
127 21 8 -33 0 0 14 14 55 9 319 -32 126 48 40 127 53 49 125 52 3 128 51 53
126 26 6 -32 0 0 14 14 52 10 320 -32 125 54 20 126 58 3 124 58 56 127 54 48
125 33 16 -31 0 0 14 14 48 11 320 -33 125 2 10 126 4 32 124 7 53 127 0 4
124 42 29 -30 0 0 14 14 44 13 321 -34 124 12 0 125 13 8 123 18 46 126 7 32
123 53 37 -29 0 0 14 14 40 14 321 -34 123 23 42 124 23 41 122 31 26 125 17 2
123 6 31 -28 0 0 14 14 35 15 321 -35 122 37 8 123 36 3 121 45 47 124 28 25
122 21 6 -27 0 0 14 14 30 16 322 -35 121 52 13 122 50 7 121 1 43 123 41 34
121 37 14 -26 0 0 14 14 25 18 322 -36 121 8 48 122 5 47 120 19 6 122 56 23
120 54 49 -25 0 0 14 14 19 19 322 -36 120 26 50 121 22 56 119 37 52 122 12 45
120 13 48 -24 0 0 14 14 13 20 323 -37 119 46 13 120 41 30 118 57 57 121 30 33
119 34 3 -23 0 0 14 14 7 21 323 -37 119 6 51 120 1 22 118 19 14 120 49 44
118 55 32 -22 0 0 14 14 0 22 323 -38 118 28 41 119 22 29 117 41 41 120 10 12
118 18 9 -21 0 0 14 13 53 23 323 -38 117 51 38 118 44 46 117 5 13 119 31 52
117 41 51 -20 0 0 14 13 46 25 323 -39 117 15 39 118 8 9 116 29 46 118 54 41
117 6 35 -19 0 0 14 13 39 26 324 -39 116 40 41 117 32 35 115 55 18 118 18 35
116 32 17 -18 0 0 14 13 31 27 324 -39 116 6 39 116 58 0 115 21 44 117 43 30
Uncertainty in time = +/- 10 secs
[Prediction of 2008 Dec 3.0]
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
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