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Updated: 2017 APR 12, 17:32 UT
Event Rank : 74
(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 2017 Jun 07 UT, the 71 km diameter asteroid (718) Erida will occult a 12.5 mag star in the constellation Capricornus for observers along a broad, somewhat uncertain path across Australa, from near Cape York across eastern Queensland to Goondiwindi and across north-eastern New South Wales to Newcastle.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.28 mag to 14.60 mag (the magnitude of the asteroid) for at most 20.9 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
140 54 23 - 9 0 0 18 27 29 73 158 -33 140 33 42 141 15 5 140 8 4 141 40 45 0.01
141 17 6 -10 0 0 18 28 4 74 158 -33 140 56 20 141 37 52 140 30 37 142 3 37 0.01
141 40 1 -11 0 0 18 28 40 75 159 -33 141 19 10 142 0 51 140 53 21 142 26 43 0.00
142 3 9 -12 0 0 18 29 15 76 159 -32 141 42 13 142 24 6 141 16 17 142 50 5 0.00
142 26 33 -13 0 0 18 29 51 77 160 -32 142 5 31 142 47 36 141 39 28 143 13 43 0.00
142 50 15 -14 0 0 18 30 27 79 160 -32 142 29 6 143 11 24 142 2 54 143 37 39 0.00
143 14 15 -15 0 0 18 31 3 80 161 -32 142 53 0 143 35 32 142 26 39 144 1 57 -0.01
143 38 37 -16 0 0 18 31 40 81 162 -32 143 17 14 144 0 2 142 50 43 144 26 36 -0.01
144 3 22 -17 0 0 18 32 16 82 163 -31 143 41 50 144 24 55 143 15 9 144 51 41 -0.01
144 28 32 -18 0 0 18 32 53 83 165 -31 144 6 50 144 50 14 143 39 58 145 17 12 -0.02
144 54 9 -19 0 0 18 33 30 84 168 -31 144 32 18 145 16 2 144 5 14 145 43 12 -0.02
145 20 16 -20 0 0 18 34 7 85 171 -31 144 58 14 145 42 19 144 30 57 146 9 43 -0.02
145 46 55 -21 0 0 18 34 45 86 177 -30 145 24 41 146 9 10 144 57 10 146 36 47 -0.02
146 14 8 -22 0 0 18 35 22 87 188 -30 145 51 42 146 36 35 145 23 56 147 4 29 -0.03
146 41 58 -23 0 0 18 35 59 87 209 -30 146 19 20 147 4 39 145 51 17 147 32 49 -0.04
147 10 29 -24 0 0 18 36 37 87 245 -29 146 47 36 147 33 23 146 19 17 148 1 51 -0.04
147 39 42 -25 0 0 18 37 15 87 277 -29 147 16 34 148 2 52 146 47 57 148 31 38 -0.04
148 9 41 -26 0 0 18 37 53 86 295 -29 147 46 18 148 33 7 147 17 21 149 2 14 -0.04
148 40 31 -27 0 0 18 38 31 85 304 -28 148 16 50 149 4 14 147 47 32 149 33 42 -0.04
Latitude Latitude Latitude Latitude
149 0 0 -27 37 6 18 38 54 85 307 -28 -28 22 2 -26 51 57 -29 17 29 -25 55 40 -0.04
150 0 0 -29 27 12 18 40 4 83 313 -27 -30 10 46 -28 43 25 -31 4 32 -27 48 51 -0.04
151 0 0 -31 11 19 18 41 11 81 316 -27 -31 53 34 -30 28 52 -32 45 43 -29 35 58 -0.05
152 0 0 -32 49 43 18 42 14 79 317 -26 -33 30 42 -32 8 33 -34 21 17 -31 17 15 -0.05
153 0 0 -34 22 42 18 43 13 77 318 -25 -35 2 28 -33 42 45 -35 51 34 -32 52 58 -0.05
154 0 0 -35 50 32 18 44 10 75 318 -25 -36 29 9 -35 11 45 -37 16 50 -34 23 26 -0.06
155 0 0 -37 13 32 18 45 3 74 318 -24 -37 51 4 -36 35 51 -38 37 24 -35 48 55 -0.06
Uncertainty in time = +/- 13 secs
Prediction of 2017 Apr 12.0
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