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Updated: 2013 AUG 13, 01:03 UT
Event Rank : 99
(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 2013 Sep 15 UT, the 140 km diameter asteroid (47) Aglaja will occult a 12.1 mag star in the constellation Sagittarius for observers along a path across Western Australia from Ravensthorpe to Broome.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.7 mag to 12.0 mag (the magnitude of the asteroid) for at most 39.3 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 Limit1 Path Limit2 Error Limit1 Error Limit2
E. Longitude Latitude U.T. Alt Az Alt
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
120 44 10 -35 8 44 15 24 30 50 271 -57 119 44 36 -35 6 16 121 44 31 -35 10 44 119 8 3 -35 4 29 122 22 19 -35 11 43
120 40 57 -34 1 19 15 25 5 50 270 -58 119 42 9 -33 58 53 121 40 30 -34 3 16 119 6 4 -33 57 9 122 17 49 -34 4 14
120 38 54 -32 53 52 15 25 40 50 268 -59 119 40 49 -32 51 29 121 37 43 -32 55 46 119 5 10 -32 49 47 122 14 35 -32 56 43
120 37 59 -31 46 22 15 26 15 50 267 -60 119 40 34 -31 44 4 121 36 9 -31 48 13 119 5 19 -31 42 24 122 12 36 -31 49 8
120 38 12 -30 38 48 15 26 50 50 266 -62 119 41 23 -30 36 33 121 35 46 -30 40 35 119 6 31 -30 34 56 122 11 49 -30 41 27
120 39 32 -29 31 7 15 27 25 49 264 -63 119 43 16 -29 28 57 121 36 31 -29 32 49 119 8 44 -29 27 23 122 12 14 -29 33 38
120 41 57 -28 23 18 15 28 0 49 263 -64 119 46 11 -28 21 13 121 38 26 -28 24 55 119 11 58 -28 19 42 122 13 50 -28 25 40
120 45 27 -27 15 18 15 28 35 49 261 -65 119 50 9 -27 13 19 121 41 29 -27 16 49 119 16 13 -27 11 51 122 16 35 -27 17 31
120 50 3 -26 7 5 15 29 10 48 260 -66 119 55 10 -26 5 12 121 45 40 -26 8 30 119 21 29 -26 3 49 122 20 31 -26 9 8
120 55 44 -24 58 38 15 29 45 48 259 -67 120 1 13 -24 56 52 121 50 59 -24 59 56 119 27 46 -24 55 33 122 25 37 -25 0 30
121 2 32 -23 49 54 15 30 20 47 258 -68 120 8 20 -23 48 15 121 57 28 -23 51 4 119 35 5 -23 47 1 122 31 54 -23 51 33
121 10 27 -22 40 50 15 30 55 47 256 -70 120 16 31 -22 39 20 122 5 7 -22 41 52 119 43 27 -22 38 10 122 39 23 -22 42 17
121 19 31 -21 31 25 15 31 31 46 255 -71 120 25 49 -21 30 3 122 13 58 -21 32 18 119 52 53 -21 28 59 122 48 6 -21 32 36
121 29 46 -20 21 35 15 32 6 46 254 -72 120 36 15 -20 20 23 122 24 2 -20 22 19 120 3 26 -20 19 24 122 58 4 -20 22 31
121 41 14 -19 11 18 15 32 41 45 253 -73 120 47 51 -19 10 16 122 35 23 -19 11 51 120 15 7 -19 9 24 123 9 21 -19 11 56
121 53 58 -18 0 30 15 33 16 45 252 -74 121 0 40 -17 59 40 122 48 2 -18 0 51 120 28 0 -17 58 54 123 21 58 -18 0 49
122 8 1 -16 49 9 15 33 51 44 251 -76 121 14 45 -16 48 30 123 2 4 -16 49 17 120 42 7 -16 47 52 123 36 0 -16 49 7
122 23 27 -15 37 10 15 34 26 43 249 -77 121 30 10 -15 36 45 123 17 33 -15 37 5 120 57 31 -15 36 14 123 51 31 -15 36 46
122 40 21 -14 24 30 15 35 1 42 248 -78 121 46 59 -14 24 19 123 34 33 -14 24 9 121 14 18 -14 23 57 124 8 35 -14 23 40
Uncertainty in time = +/- 12 secs
Prediction of 2013 Aug 13.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
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