|
|
Updated: 2012 Jun 06, 03:17 UT
Event Rank : 6
(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 Jul 19 UT, the 11 km diameter asteroid (32497) 2000 XF18 will occult a 8.3 mag star in the constellation Scorpius for observers along a large uncertainty path across eastern Queensland and eastern New South Wales. The predicted shadow path runs from Sydney to Rockhampton.
In the case of an occultation, the combined light of the asteroid and the star will drop by 7.6 mag to 15.9 mag (the magnitude of the asteroid) for at most 1.5 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: .
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.
Occultation of HIP 82447 by 32497 2000 XF18 on 2012 Jul 19
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
151 13 39 -44 0 45 9 2 28 67 82 -25 151 9 13 -44 0 30 151 18 4 -44 1 1 149 26 10 -43 53 39 153 0 29 -44 6 17
151 20 58 -42 41 2 9 2 49 67 85 -25 151 16 38 -42 40 46 151 25 18 -42 41 17 149 35 49 -42 34 8 153 5 29 -42 46 24
151 26 44 -41 21 20 9 3 10 68 88 -25 151 22 29 -41 21 6 151 30 59 -41 21 35 149 43 45 -41 14 38 153 9 5 -41 26 34
151 31 5 -40 1 39 9 3 30 68 91 -25 151 26 55 -40 1 25 151 35 14 -40 1 54 149 50 7 -39 55 6 153 11 24 -40 6 45
151 34 6 -38 41 56 9 3 51 68 94 -25 151 30 1 -38 41 41 151 38 10 -38 42 10 149 55 0 -38 35 30 153 12 32 -38 46 55
151 35 52 -37 22 8 9 4 12 68 97 -25 151 31 51 -37 21 54 151 39 52 -37 22 22 149 58 32 -37 15 48 153 12 33 -37 27 2
151 36 28 -36 2 13 9 4 33 68 101 -25 151 32 32 -36 1 59 151 40 25 -36 2 26 150 0 47 -35 55 59 153 11 31 -36 7 3
151 35 59 -34 42 8 9 4 54 67 104 -25 151 32 6 -34 41 55 151 39 51 -34 42 22 150 1 49 -34 35 58 153 9 30 -34 46 56
151 34 27 -33 21 52 9 5 15 67 107 -24 151 30 37 -33 21 39 151 38 16 -33 22 6 150 1 43 -33 15 45 153 6 32 -33 26 38
151 31 54 -32 1 22 9 5 36 67 110 -24 151 28 9 -32 1 8 151 35 40 -32 1 35 150 0 31 -31 55 16 153 2 39 -32 6 7
151 28 25 -30 40 34 9 5 57 66 113 -24 151 24 42 -30 40 20 151 32 8 -30 40 47 149 58 16 -30 34 29 152 57 55 -30 45 19
151 24 0 -29 19 26 9 6 18 66 116 -24 151 20 20 -29 19 12 151 27 40 -29 19 39 149 55 0 -29 13 20 152 52 21 -29 24 12
151 18 41 -27 57 55 9 6 39 65 118 -23 151 15 4 -27 57 41 151 22 18 -27 58 8 149 50 46 -27 51 48 152 45 57 -28 2 43
151 12 30 -26 35 58 9 7 0 64 121 -23 151 8 55 -26 35 44 151 16 5 -26 36 12 149 45 34 -26 29 49 152 38 46 -26 40 49
151 5 27 -25 13 32 9 7 21 64 123 -23 151 1 55 -25 13 18 151 9 0 -25 13 45 149 39 26 -25 7 19 152 30 48 -25 18 27
150 57 33 -23 50 33 9 7 42 63 125 -22 150 54 3 -23 50 19 151 1 4 -23 50 47 149 32 23 -23 44 15 152 22 3 -23 55 33
150 48 49 -22 26 58 9 8 3 62 127 -22 150 45 20 -22 26 43 150 52 17 -22 27 12 149 24 25 -22 20 34 152 12 31 -22 32 3
150 39 14 -21 2 42 9 8 24 61 129 -22 150 35 47 -21 2 27 150 42 40 -21 2 56 149 15 33 -20 56 11 152 2 13 -21 7 55
150 28 47 -19 37 42 9 8 45 60 131 -21 150 25 22 -19 37 27 150 32 12 -19 37 57 149 5 44 -19 31 3 151 51 8 -19 43 3
150 17 29 -18 11 53 9 9 6 59 133 -21 150 14 5 -18 11 38 150 20 53 -18 12 8 148 55 0 -18 5 5 151 39 15 -18 17 23
Uncertainty in time = +/- 19 secs
Prediction of 2012 Jun 6.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
[Asteroid Occultation Results]
[Top of Page][Return to Home Page]