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Updated: 2018 AUG 12, 18:10 UT
Event Rank : 97
(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 2018 Sep 29 UT, the 100.9 km diameter asteroid (694) Ekard will occult a 9.7 mag star in the constellation Triangulum for observers along a path across Australia from Gove Peninsula across The Northern Territory and western South Australia to Eucla in south-east Western Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.95 mag to 11.44 mag (the magnitude of the asteroid) for at most 16.4 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, astrometry for the asteroid kindly provided by Bill Owen, astrometry for the asteroid kindly provided by the IAU Minor Planet Center.
This work has made use of data from the European Space Agency (ESA) mission Gaia (http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, http://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.
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 Alt
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 Crn
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
129 0 37 -34 0 0 17 57 38 26 341 -37 128 16 19 129 45 18 127 48 32 130 13 41 0.88
129 9 54 -33 0 0 17 57 28 26 341 -37 128 26 1 129 54 9 127 58 31 130 22 15 0.88
129 20 10 -32 0 0 17 57 17 27 341 -38 128 36 41 130 4 0 128 9 26 130 31 51 0.88
129 31 23 -31 0 0 17 57 6 28 341 -38 128 48 16 130 14 51 128 21 15 130 42 27 0.88
129 43 33 -30 0 0 17 56 55 29 340 -39 129 0 46 130 26 39 128 33 58 130 54 2 0.88
129 56 38 -29 0 0 17 56 43 30 340 -39 129 14 11 130 39 25 128 47 34 131 6 36 0.88
130 10 37 -28 0 0 17 56 31 31 340 -40 129 28 28 130 53 8 129 2 2 131 20 7 0.88
130 25 31 -27 0 0 17 56 19 32 339 -40 129 43 38 131 7 45 129 17 22 131 34 35 0.88
130 41 18 -26 0 0 17 56 6 33 339 -40 129 59 39 131 23 18 129 33 33 131 49 58 0.88
130 57 59 -25 0 0 17 55 53 34 338 -41 130 16 33 131 39 45 129 50 34 132 6 17 0.88
131 15 32 -24 0 0 17 55 40 34 338 -41 130 34 17 131 57 6 130 8 26 132 23 31 0.88
131 33 57 -23 0 0 17 55 26 35 337 -41 130 52 53 132 15 22 130 27 9 132 41 40 0.88
131 53 15 -22 0 0 17 55 12 36 337 -41 131 12 20 132 34 31 130 46 41 133 0 43 0.88
132 13 26 -21 0 0 17 54 58 37 336 -41 131 32 38 132 54 34 131 7 4 133 20 41 0.88
132 34 29 -20 0 0 17 54 43 38 336 -42 131 53 48 133 15 31 131 28 18 133 41 35 0.88
132 56 25 -19 0 0 17 54 28 38 335 -42 132 15 49 133 37 22 131 50 22 134 3 23 0.88
133 19 15 -18 0 0 17 54 13 39 334 -42 132 38 42 134 0 8 132 13 18 134 26 7 0.87
133 42 58 -17 0 0 17 53 57 40 334 -42 133 2 28 134 23 50 132 37 5 134 49 47 0.87
134 7 36 -16 0 0 17 53 41 41 333 -42 133 27 7 134 48 27 133 1 45 135 14 25 0.87
134 33 10 -15 0 0 17 53 25 41 332 -42 133 52 40 135 14 1 133 27 17 135 39 59 0.87
134 59 39 -14 0 0 17 53 8 42 331 -42 134 19 7 135 40 33 133 53 44 136 6 32 0.87
135 27 6 -13 0 0 17 52 51 43 330 -42 134 46 31 136 8 3 134 21 6 136 34 5 0.87
135 55 31 -12 0 0 17 52 34 43 330 -42 135 14 51 136 36 33 134 49 23 137 2 38 0.87
136 24 55 -11 0 0 17 52 17 44 329 -41 135 44 10 137 6 4 135 18 38 137 32 14 0.86
136 55 21 -10 0 0 17 51 59 45 328 -41 136 14 28 137 36 38 135 48 52 138 2 53 0.86
137 26 50 - 9 0 0 17 51 41 45 327 -41 136 45 47 138 8 16 136 20 6 138 34 37 0.86
137 59 23 - 8 0 0 17 51 22 46 326 -41 137 18 9 138 41 0 136 52 22 139 7 29 0.86
138 33 2 - 7 0 0 17 51 3 46 325 -40 137 51 36 139 14 53 137 25 41 139 41 30 0.86
139 7 50 - 6 0 0 17 50 44 47 324 -40 138 26 10 139 49 56 138 0 6 140 16 43 0.86
139 43 49 - 5 0 0 17 50 25 47 322 -40 139 1 54 140 26 12 138 35 40 140 53 10 0.85
140 21 3 - 4 0 0 17 50 5 48 321 -39 139 38 49 141 3 44 139 12 24 141 30 55 0.85
140 59 32 - 3 0 0 17 49 45 48 320 -39 140 16 58 141 42 35 139 50 21 142 9 59 0.85
141 39 22 - 2 0 0 17 49 25 49 319 -38 140 56 26 142 22 48 140 29 35 142 50 28 0.85
142 20 36 - 1 0 0 17 49 5 49 317 -38 141 37 14 143 4 27 141 10 9 143 32 24 0.85
143 3 16 0 0 0 17 48 44 49 316 -37 142 19 28 143 47 37 141 52 6 144 15 53 0.84
143 47 29 1 0 0 17 48 22 50 315 -37 143 3 11 144 32 21 142 35 31 145 0 58 0.84
Latitude Latitude Latitude Latitude
144 0 0 1 16 36 17 48 17 50 314 -37 2 14 57 0 16 50 2 51 6 - 0 21 40 0.84
-143 0 0 .. .. .. .. .. .. .. .. .. 20 14 37 .. .. .. .. .. .. .. .. .. ....
Uncertainty in time = +/- 6 secs
Prediction of 2018 Aug 12.0
Use these links for further information:
[Planetary Occultations]
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[Observing Details]
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