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Updated: 2005 DEC 20, 22:09 UT
Event Rank : 19
(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 2006 Jan 20 UT, the 20 km diameter asteroid (1238) Predappia will occult a 11.0 mag star in the constellation Lynx for observers along a path across central Western Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 4.0 mag to 15.0 mag (the magnitude of the asteroid) for at most 2.1 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Ron Stone, 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
136 41 15 -44 0 0 16 41 56 8 350 -22 136 53 41 136 28 47 138 19 59 135 0 37
136 12 22 -43 0 0 16 41 59 9 351 -23 136 24 41 136 0 2 137 50 4 134 32 48
135 42 25 -42 0 0 16 42 2 10 351 -24 135 54 36 135 30 12 137 19 10 134 3 47
135 11 23 -41 0 0 16 42 5 11 352 -25 135 23 28 134 59 16 136 47 17 133 33 36
134 39 16 -40 0 0 16 42 9 12 352 -27 134 51 15 134 27 15 136 14 24 133 2 15
134 6 4 -39 0 0 16 42 13 13 352 -28 134 17 58 133 54 8 135 40 31 132 29 44
133 31 46 -38 0 0 16 42 17 14 353 -29 133 43 36 133 19 55 135 5 37 131 56 2
132 56 22 -37 0 0 16 42 22 15 353 -30 133 8 8 132 44 34 134 29 42 131 21 7
132 19 51 -36 0 0 16 42 27 16 354 -31 132 31 33 132 8 6 133 52 44 130 45 1
131 42 10 -35 0 0 16 42 33 17 354 -32 131 53 50 131 30 28 133 14 42 130 7 40
131 3 20 -34 0 0 16 42 39 18 355 -33 131 14 58 130 51 39 132 35 35 129 29 4
130 23 17 -33 0 0 16 42 45 19 355 -34 130 34 54 130 11 38 131 55 21 128 49 11
129 42 0 -32 0 0 16 42 52 20 356 -35 129 53 36 129 30 22 131 13 57 128 7 59
128 59 27 -31 0 0 16 43 0 21 356 -37 129 11 3 128 47 49 130 31 23 127 25 25
128 15 35 -30 0 0 16 43 7 22 357 -38 128 27 12 128 3 57 129 47 34 126 41 26
127 30 22 -29 0 0 16 43 15 23 357 -39 127 42 0 127 18 42 129 2 29 125 56 0
126 43 43 -28 0 0 16 43 24 24 358 -40 126 55 23 126 32 1 128 16 5 125 9 3
125 55 36 -27 0 0 16 43 33 25 359 -41 126 7 18 125 43 51 127 28 18 124 20 30
125 5 55 -26 0 0 16 43 42 26 359 -42 125 17 42 124 54 7 126 39 4 123 30 18
124 14 37 -25 0 0 16 43 52 27 360 -43 124 26 28 124 2 44 125 48 18 122 38 22
123 21 37 -24 0 0 16 44 3 28 1 -45 123 33 33 123 9 38 124 55 58 121 44 34
122 26 47 -23 0 0 16 44 14 29 2 -46 122 38 50 122 14 42 124 1 56 120 48 50
121 30 3 -22 0 0 16 44 25 30 2 -47 121 42 13 121 17 50 123 6 7 119 51 1
120 31 16 -21 0 0 16 44 37 31 3 -48 120 43 34 120 18 55 122 8 24 118 50 59
119 30 17 -20 0 0 16 44 50 32 4 -49 119 42 46 119 17 46 121 8 40 117 48 35
118 26 58 -19 0 0 16 45 3 33 5 -50 118 39 38 118 14 15 120 6 47 116 43 37
117 21 7 -18 0 0 16 45 17 34 6 -52 117 33 59 117 8 10 119 2 33 115 35 51
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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