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Updated: 2009 JUN 24, 17:21 UT
Event Rank : 85
(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 2009 Jul 05 UT, the 99 km diameter asteroid (694) Ekard will occult a 10.6 mag star in the constellation Delphinus for observers along a path across Western Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.4 mag to 11.6 mag (the magnitude of the asteroid) for at most 13.6 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.
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
125 53 25 -37 0 0 16 10 35 41 20 -74 126 34 31 125 12 9 127 22 48 124 23 12
125 33 12 -36 0 0 16 10 48 42 20 -75 126 13 52 124 52 22 127 1 39 124 3 57
125 12 32 -35 0 0 16 11 0 43 21 -76 125 52 47 124 32 7 126 40 5 123 44 10
124 51 24 -34 0 0 16 11 12 44 22 -77 125 31 16 124 11 22 126 18 6 123 23 53
124 29 49 -33 0 0 16 11 25 45 22 -78 125 9 19 123 50 8 125 55 44 123 3 5
124 7 46 -32 0 0 16 11 38 45 23 -79 124 46 56 123 28 26 125 32 56 122 41 47
123 45 16 -31 0 0 16 11 51 46 24 -80 124 24 7 123 6 14 125 9 45 122 19 58
123 22 18 -30 0 0 16 12 5 47 25 -81 124 0 51 122 43 34 124 46 8 121 57 38
122 58 51 -29 0 0 16 12 19 48 26 -82 123 37 8 122 20 24 124 22 5 121 34 48
122 34 57 -28 0 0 16 12 32 48 27 -83 123 12 58 121 56 45 123 57 38 121 11 27
122 10 34 -27 0 0 16 12 46 49 28 -84 122 48 21 121 32 36 123 32 44 120 47 35
121 45 43 -26 0 0 16 13 1 50 29 -85 122 23 17 121 7 58 123 7 24 120 23 11
121 20 22 -25 0 0 16 13 15 51 30 -86 121 57 44 120 42 49 122 41 37 119 58 16
120 54 31 -24 0 0 16 13 30 51 31 -86 121 31 43 120 17 9 122 15 23 119 32 49
120 28 11 -23 0 0 16 13 44 52 32 -87 121 5 13 119 50 58 121 48 41 119 6 49
120 1 20 -22 0 0 16 13 59 53 33 -87 120 38 13 119 24 15 121 21 31 118 40 16
119 33 57 -21 0 0 16 14 14 53 35 -87 120 10 43 118 57 0 120 53 52 118 13 10
119 6 3 -20 0 0 16 14 30 54 36 -86 119 42 42 118 29 13 120 25 44 117 45 30
118 37 36 -19 0 0 16 14 45 54 37 -86 119 14 10 118 0 51 119 57 5 117 17 14
118 8 36 -18 0 0 16 15 1 55 39 -85 118 45 5 117 31 55 119 27 54 116 48 23
Uncertainty in time = +/- 8 secs
Prediction of 2009 Jun 25.0
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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