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Updated: 2011 Jul 01, 22:55 UT
Event Rank : 87
(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 2011 Jul 16 UT, the 32 km diameter asteroid (1036) Ganymed will occult a 10.9 mag star in the constellation Cygnus for observers along a path across central Western Australia, low in the northern sky.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.7 mag to 10.8 mag (the magnitude of the asteroid) for at most 2.5 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.
Occultation of TYC 3603-03086-1 by 1036 Ganymed on 2011 Jul 16
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
123 9 12 -25 0 0 14 47 54 3 26 -74 123 19 58 122 58 24 123 32 27 122 45 52
123 40 22 -24 0 0 14 47 55 4 26 -75 123 51 1 123 29 42 124 3 21 123 17 18
124 10 40 -23 0 0 14 47 55 5 26 -76 124 21 12 124 0 7 124 33 25 123 47 52
124 40 10 -22 0 0 14 47 56 6 26 -76 124 50 35 124 29 43 125 2 40 124 17 36
125 8 53 -21 0 0 14 47 57 7 25 -76 125 19 12 124 58 33 125 31 9 124 46 32
125 36 51 -20 0 0 14 47 59 8 25 -77 125 47 5 125 26 37 125 58 56 125 14 44
126 4 8 -19 0 0 14 48 0 10 25 -77 126 14 16 125 54 0 126 26 1 125 42 13
126 30 46 -18 0 0 14 48 2 11 25 -77 126 40 48 126 20 42 126 52 27 126 9 1
126 56 45 -17 0 0 14 48 4 12 25 -77 127 6 43 126 46 46 127 18 16 126 35 11
127 22 8 -16 0 0 14 48 6 13 25 -77 127 32 2 127 12 14 127 43 29 127 0 45
127 46 57 -15 0 0 14 48 8 14 25 -77 127 56 47 127 37 8 128 8 9 127 25 43
128 11 14 -14 0 0 14 48 10 15 25 -77 128 20 59 128 1 28 128 32 17 127 50 8
128 34 59 -13 0 0 14 48 13 16 25 -77 128 44 41 128 25 17 128 55 55 128 14 2
128 58 15 -12 0 0 14 48 15 17 24 -76 129 7 53 128 48 37 129 19 3 128 37 25
129 21 3 -11 0 0 14 48 18 18 24 -76 129 30 37 129 11 27 129 41 44 129 0 19
129 43 23 -10 0 0 14 48 21 19 24 -75 129 52 55 129 33 51 130 3 58 129 22 47
Uncertainty in time = +/- 2 secs
Prediction of 2011 Jul 2.0
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[Using the Predictions]
[Observing Details]
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[Reporting Details]
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