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Updated: 2009 MAR 18, 17:51 UT
Event Rank : 72
(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 Apr 04 UT, the 106 km diameter asteroid (36) Atalante will occult a 12.4 mag star in the constellation Scorpius for observers along a path across Western Australia, from Broome to Point Dover.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 14.4 mag (the magnitude of the asteroid) for at most 9.2 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
119 21 23 -10 0 0 18 36 28 44 143 -52 118 49 13 119 53 28 117 56 55 120 45 15
119 40 26 -11 0 0 18 36 36 45 143 -52 119 8 13 120 12 33 118 15 51 121 4 25
119 59 12 -12 0 0 18 36 44 46 143 -52 119 26 56 120 31 23 118 34 29 121 23 21
120 17 44 -13 0 0 18 36 51 47 142 -51 119 45 23 120 49 59 118 52 49 121 42 4
120 36 0 -14 0 0 18 36 59 48 142 -51 120 3 35 121 8 20 119 10 53 122 0 34
120 54 3 -15 0 0 18 37 7 49 141 -50 120 21 32 121 26 29 119 28 41 122 18 51
121 11 52 -16 0 0 18 37 15 50 141 -50 120 39 15 121 44 25 119 46 13 122 36 58
121 29 29 -17 0 0 18 37 23 51 140 -49 120 56 45 122 2 9 120 3 32 122 54 54
121 46 54 -18 0 0 18 37 32 52 140 -49 121 14 2 122 19 42 120 20 36 123 12 41
122 4 8 -19 0 0 18 37 40 53 139 -48 121 31 7 122 37 5 120 37 27 123 30 18
122 21 12 -20 0 0 18 37 49 54 138 -48 121 48 1 122 54 18 120 54 6 123 47 47
122 38 6 -21 0 0 18 37 57 55 137 -47 122 4 45 123 11 23 121 10 33 124 5 9
122 54 51 -22 0 0 18 38 6 56 137 -47 122 21 19 123 28 19 121 26 49 124 22 24
123 11 28 -23 0 0 18 38 15 56 136 -46 122 37 43 123 45 8 121 42 54 124 39 32
123 27 56 -24 0 0 18 38 23 57 135 -46 122 53 59 124 1 50 121 58 49 124 56 36
123 44 18 -25 0 0 18 38 32 58 134 -45 123 10 7 124 18 26 122 14 34 125 13 34
124 0 34 -26 0 0 18 38 41 59 133 -44 123 26 7 124 34 56 122 30 11 125 30 29
124 16 43 -27 0 0 18 38 50 60 132 -44 123 42 1 124 51 22 122 45 39 125 47 20
124 32 48 -28 0 0 18 39 0 61 131 -43 123 57 49 125 7 43 123 1 0 126 4 9
124 48 48 -29 0 0 18 39 9 62 130 -43 124 13 32 125 24 1 123 16 13 126 20 56
125 4 45 -30 0 0 18 39 18 62 128 -42 124 29 9 125 40 17 123 31 21 126 37 43
125 20 39 -31 0 0 18 39 27 63 127 -41 124 44 43 125 56 31 123 46 22 126 54 29
125 36 30 -32 0 0 18 39 37 64 125 -41 125 0 13 126 12 43 124 1 18 127 11 17
125 52 20 -33 0 0 18 39 46 65 124 -40 125 15 41 126 28 56 124 16 9 127 28 6
126 8 9 -34 0 0 18 39 56 66 122 -40 125 31 6 126 45 9 124 30 56 127 44 57
126 23 58 -35 0 0 18 40 5 66 120 -39 125 46 30 127 1 23 124 45 40 128 1 52
126 39 48 -36 0 0 18 40 15 67 118 -38 126 1 54 127 17 39 125 0 21 128 18 52
126 55 40 -37 0 0 18 40 25 68 116 -38 126 17 18 127 33 59 125 15 0 128 35 57
Uncertainty in time = +/- 8 secs
Prediction of 2009 Mar 19.0
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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