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Updated: 2009 SEP 07, 00:57 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 2009 Oct 10 UT, the 12 km diameter asteroid (5290) Langevin will occult a 10.5 mag star in the constellation Orion for observers along a narrow, significant uncertainty path across central Australia, running from Darwin to Eucla.
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.3 mag to 16.8 mag (the magnitude of the asteroid) for at most 1.9 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 0 53 -37 0 0 14 57 14 8 69 -45 122 44 39 123 16 49 116 56 12 127 16 47
124 21 2 -36 0 0 14 57 4 9 68 -47 124 6 16 124 35 35 119 4 54 128 18 31
125 29 58 -35 0 0 14 56 53 11 68 -48 125 16 17 125 43 28 120 45 30 129 13 2
126 29 54 -34 0 0 14 56 42 12 67 -49 126 17 4 126 42 35 122 8 7 130 1 22
127 22 21 -33 0 0 14 56 30 13 67 -50 127 10 12 127 34 22 123 17 46 130 44 16
128 8 24 -32 0 0 14 56 17 14 67 -51 127 56 48 128 19 53 124 17 19 131 22 21
128 48 53 -31 0 0 14 56 4 15 67 -52 128 37 44 128 59 55 125 8 41 131 56 6
129 24 25 -30 0 0 14 55 51 15 66 -53 129 13 40 129 35 5 125 53 7 132 25 54
129 55 29 -29 0 0 14 55 37 16 66 -54 129 45 4 130 5 50 126 31 36 132 52 5
130 22 31 -28 0 0 14 55 23 17 66 -55 130 12 22 130 32 35 127 4 48 133 14 54
130 45 48 -27 0 0 14 55 8 17 67 -56 130 35 53 130 55 38 127 33 15 133 34 35
131 5 35 -26 0 0 14 54 53 18 67 -57 130 55 52 131 15 14 127 57 23 133 51 18
131 22 7 -25 0 0 14 54 38 19 67 -58 131 12 34 131 31 36 128 17 32 134 5 13
131 35 32 -24 0 0 14 54 23 19 67 -59 131 26 8 131 44 53 128 33 56 134 16 27
131 46 0 -23 0 0 14 54 7 20 67 -60 131 36 42 131 55 14 128 46 49 134 25 6
131 53 36 -22 0 0 14 53 51 20 68 -61 131 44 24 132 2 45 128 56 20 134 31 15
131 58 26 -21 0 0 14 53 35 20 68 -62 131 49 18 132 7 31 129 2 35 134 34 59
132 0 34 -20 0 0 14 53 18 21 68 -63 131 51 29 132 9 36 129 5 41 134 36 19
132 0 2 -19 0 0 14 53 1 21 69 -64 131 50 58 132 9 2 129 5 39 134 35 18
131 56 51 -18 0 0 14 52 44 21 69 -65 131 47 48 132 5 51 129 2 32 134 31 57
131 51 1 -17 0 0 14 52 26 22 70 -66 131 41 57 132 0 2 128 56 20 134 26 17
131 42 31 -16 0 0 14 52 9 22 70 -67 131 33 25 131 51 34 128 46 59 134 18 16
131 31 19 -15 0 0 14 51 51 22 71 -68 131 22 9 131 40 25 128 34 26 134 7 52
131 17 20 -14 0 0 14 51 32 22 71 -69 131 8 5 131 26 31 128 18 34 133 55 4
131 0 29 -13 0 0 14 51 14 22 72 -70 130 51 8 131 9 46 127 59 15 133 39 47
130 40 40 -12 0 0 14 50 55 22 72 -71 130 31 11 130 50 5 127 36 17 133 21 57
130 17 42 -11 0 0 14 50 36 22 73 -72 130 8 3 130 27 17 127 9 24 133 1 27
129 51 24 -10 0 0 14 50 16 21 73 -73 129 41 32 130 1 11 126 38 15 132 38 10
Uncertainty in time = +/- 16 secs
Prediction of 2009 Sep 7.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
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