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Updated: 2012 APR 19, 00:00 UT
Event Rank : 18
(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 Jun 10 UT, the 20 km diameter asteroid (1886) Lowell will occult a 9.2 mag star in the constellation Leo for observers along a narrow path across Western Australia from Dampier at sunset to Eucla just after evening twilight.
In the case of an occultation, the combined light of the asteroid and the star will drop by 8.3 mag to 17.5 mag (the magnitude of the asteroid) for at most 1.0 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
131 15 41 -37 0 0 9 28 59 33 357 -16 131 6 15 131 25 6 129 55 39 132 35 9
130 33 53 -36 0 0 9 28 55 34 358 -15 130 24 32 130 43 13 129 14 34 131 52 37
129 51 58 -35 0 0 9 28 50 35 359 -15 129 42 42 130 1 14 128 33 18 131 10 2
129 9 54 -34 0 0 9 28 46 36 360 -14 129 0 42 129 19 5 127 51 50 130 27 21
128 27 39 -33 0 0 9 28 41 37 1 -13 128 18 31 128 36 46 127 10 7 129 44 32
127 45 10 -32 0 0 9 28 36 38 1 -12 127 36 6 127 54 14 126 28 8 129 1 33
127 2 26 -31 0 0 9 28 31 39 2 -11 126 53 25 127 11 26 125 45 50 128 18 21
126 19 24 -30 0 0 9 28 26 40 3 -10 126 10 26 126 28 22 125 3 11 127 34 55
125 36 2 -29 0 0 9 28 21 41 4 -9 125 27 6 125 44 57 124 20 9 126 51 12
124 52 18 -28 0 0 9 28 15 41 5 -8 124 43 24 125 1 11 123 36 42 126 7 10
124 8 10 -27 0 0 9 28 10 42 6 -7 123 59 18 124 17 2 122 52 48 125 22 46
123 23 35 -26 0 0 9 28 4 43 7 -6 123 14 45 123 32 25 122 8 24 124 37 59
122 38 31 -25 0 0 9 27 58 44 8 -5 122 29 42 122 47 20 121 23 28 123 52 46
121 52 56 -24 0 0 9 27 52 45 10 -4 121 44 7 122 1 44 120 37 57 123 7 5
121 6 46 -23 0 0 9 27 46 46 11 -3 120 57 57 121 15 34 119 51 49 122 20 52
120 20 0 -22 0 0 9 27 40 47 12 -2 120 11 11 120 28 48 119 5 0 121 34 6
119 32 34 -21 0 0 9 27 34 48 13 -1 119 23 44 119 41 22 118 17 29 120 46 43
Uncertainty in time = +/- 4 secs
Prediction of 2012 Apr 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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