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Updated: 2010 JUL 20, 22:26 UT
Event Rank : 52
(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 2010 Sep 09 UT, the 45 km diameter asteroid (446) Aeternitas will occult a 11.3 mag star in the constellation Sagittarius for observers along a path across central Australia from near Eucla in Western Australia to near Tennant Creek in Northern Territory at decreasing elevation.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.1 mag to 13.2 mag (the magnitude of the asteroid) for at most 6.5 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
126 20 44 -34 5 36 17 0 11 24 241 -55 125 49 19 -34 15 14 126 52 34 -33 55 35 124 33 38 -34 37 25 128 12 47 -33 29 10
126 34 36 -33 8 36 17 0 23 23 240 -55 126 2 56 -33 18 36 127 6 43 -32 58 11 124 46 45 -33 41 36 128 27 47 -32 30 41
126 50 31 -32 10 22 17 0 35 23 240 -56 126 18 32 -32 20 47 127 23 0 -31 59 30 125 1 42 -32 44 43 128 45 8 -31 30 46
127 8 39 -31 10 46 17 0 47 22 239 -56 126 36 15 -31 21 40 127 41 35 -30 59 23 125 18 35 -31 46 40 129 5 3 -30 29 11
127 29 11 -30 9 37 17 1 0 21 239 -57 126 56 17 -30 21 5 128 2 41 -29 57 38 125 37 33 -30 47 18 129 27 49 -29 25 44
127 52 23 -29 6 43 17 1 12 20 238 -57 127 18 50 -29 18 50 128 26 34 -28 54 2 125 58 48 -29 46 29 129 53 48 -28 20 6
128 18 33 -28 1 47 17 1 24 19 238 -58 127 44 13 -28 14 41 128 53 37 -27 48 15 126 22 33 -28 43 59 130 23 29 -27 11 54
128 48 8 -26 54 30 17 1 36 18 237 -58 128 12 48 -27 8 19 129 24 18 -26 39 57 126 49 6 -27 39 35 130 57 30 -26 0 36
129 21 39 -25 44 22 17 1 48 17 237 -58 128 45 5 -25 59 19 129 59 14 -25 28 34 127 18 49 -26 32 58 131 36 47 -24 45 28
129 59 55 -24 30 49 17 2 0 16 236 -58 129 21 43 -24 47 10 130 39 21 -24 13 26 127 52 13 -25 23 43 132 22 43 -23 25 25
130 44 2 -23 12 56 17 2 13 15 236 -58 130 3 41 -23 31 7 131 25 57 -22 53 28 128 29 57 -24 11 18 133 17 31 -21 58 43
131 35 44 -21 49 22 17 2 25 13 235 -58 130 52 24 -22 10 1 132 21 11 -21 27 1 129 12 59 -22 54 59 134 25 9 -20 22 19
132 37 53 -20 17 54 17 2 37 12 235 -58 131 50 10 -20 42 6 133 28 47 -19 51 12 130 2 44 -21 33 37 135 54 14 -18 29 32
133 56 4 -18 34 15 17 2 49 10 234 -58 133 1 4 -19 4 12 134 56 39 -17 59 55 131 1 29 -20 5 28 138 13 49 -15 58 8
135 44 13 -16 27 42 17 3 1 7 234 -57 134 34 7 -17 9 25 137 9 30 -15 34 15 132 13 18 -18 27 23 ... .. .. .. .. ..
139 30 48 -12 50 40 17 3 13 2 233 -54 137 0 4 -14 34 11 ... .. .. .. .. .. 133 46 57 -16 32 38 ... .. .. .. .. ..
Uncertainty in time = +/- 8 secs
Prediction of 2010 Jul 21.0
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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