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Updated: 2012 JAN 03, 13:40 UT
Event Rank : 26
(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 2012 Feb 11 UT, the 81 km diameter asteroid (5264) Telephus will occult a 11.6 mag star in the constellation Orion for observers along a quite uncertain south-to-north path across Western Australia centred from Albany to Shark Bay, passing near Perth and Northam.
In the case of an occultation, the combined light of the asteroid and the star will drop by 4.7 mag to 16.3 mag (the magnitude of the asteroid) for at most 5.5 seconds.
This update is based on TMO astrometry for the asteroid kindly provided by Bill Owen, 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
121 12 38 -45 0 0 12 0 52 36 13 -9 121 49 40 120 35 29 125 2 9 117 18 48
120 53 1 -44 0 0 12 0 57 37 14 -9 121 29 29 120 16 26 124 39 0 117 2 45
120 33 5 -43 0 0 12 1 3 37 14 -9 121 9 1 119 57 2 124 15 45 116 46 11
120 12 49 -42 0 0 12 1 8 38 15 -9 120 48 15 119 37 17 123 52 21 116 29 6
119 52 15 -41 0 0 12 1 14 39 15 -10 120 27 12 119 17 11 123 28 49 116 11 32
119 31 21 -40 0 0 12 1 19 40 16 -10 120 5 52 118 56 44 123 5 7 115 53 28
119 10 8 -39 0 0 12 1 25 41 17 -10 119 44 13 118 35 57 122 41 15 115 34 54
118 48 36 -38 0 0 12 1 31 42 17 -10 119 22 17 118 14 48 122 17 13 115 15 53
118 26 43 -37 0 0 12 1 37 43 18 -11 119 0 2 117 53 19 121 53 0 114 56 22
118 4 31 -36 0 0 12 1 43 44 19 -11 118 37 28 117 31 28 121 28 34 114 36 23
117 41 59 -35 0 0 12 1 50 44 19 -11 118 14 36 117 9 16 121 3 57 114 15 56
117 19 6 -34 0 0 12 1 56 45 20 -11 117 51 24 116 46 42 120 39 7 113 55 1
116 55 53 -33 0 0 12 2 2 46 21 -11 117 27 53 116 23 46 120 14 2 113 33 38
116 32 18 -32 0 0 12 2 9 47 22 -12 117 4 2 116 0 28 119 48 44 113 11 46
116 8 22 -31 0 0 12 2 16 48 23 -12 116 39 50 115 36 47 119 23 11 112 49 26
115 44 3 -30 0 0 12 2 22 49 24 -12 116 15 18 115 12 43 118 57 22 112 26 37
115 19 23 -29 0 0 12 2 29 49 25 -12 115 50 23 114 48 16 118 31 17 112 3 19
114 54 19 -28 0 0 12 2 36 50 26 -12 115 25 7 114 23 24 118 4 56 111 39 32
114 28 52 -27 0 0 12 2 43 51 27 -12 114 59 29 113 58 9 117 38 16 111 15 15
114 3 1 -26 0 0 12 2 51 52 28 -12 114 33 27 113 32 28 117 11 19 110 50 29
113 36 45 -25 0 0 12 2 58 52 29 -12 114 7 2 113 6 22 116 44 2 110 25 11
113 10 4 -24 0 0 12 3 5 53 31 -12 113 40 12 112 39 49 116 16 26 109 59 22
112 42 56 -23 0 0 12 3 13 54 32 -12 113 12 57 112 12 49 115 48 28 109 33 2
112 15 22 -22 0 0 12 3 20 54 33 -12 112 45 16 111 45 22 115 20 10 109 6 9
111 47 21 -21 0 0 12 3 28 55 35 -12 112 17 8 111 17 27 114 51 29 108 38 43
111 18 51 -20 0 0 12 3 36 55 36 -12 111 48 33 110 49 2 114 22 25 108 10 43
110 49 52 -19 0 0 12 3 43 56 38 -12 111 19 29 110 20 7 113 52 57 107 42 9
110 20 22 -18 0 0 12 3 51 56 39 -12 110 49 56 109 50 40 113 23 4 107 12 58
109 50 21 -17 0 0 12 3 59 57 41 -12 110 19 53 109 20 42 112 52 45 106 43 11
109 19 48 -16 0 0 12 4 7 57 43 -12 109 49 18 108 50 11 112 21 58 106 12 45
Uncertainty in time = +/- 14 secs
Prediction of 2012 Jan 3.0
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[Observing Details]
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