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Updated: 2018 JAN 17, 15:48 UT
Event Rank : 99
(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 Feb 17 UT, the 63 km diameter asteroid (67) Asia will occult a 12.4 mag star in the constellation Gemini for observers along a path passing near Eucla in WA in morning twilight.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.04 mag to 12.90 mag (the magnitude of the asteroid) for at most 8.8 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, inparticular 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
150 36 41 -48 0 0 10 29 16 27 12 -13 151 39 12 149 33 24 152 5 21 149 6 26 1.54
149 16 45 -47 0 0 10 29 33 28 13 -12 150 19 6 148 13 35 150 45 11 147 46 40 1.54
147 55 6 -46 0 0 10 29 51 29 15 -12 148 57 24 146 51 56 149 23 27 146 25 1 1.54
146 31 35 -45 0 0 10 30 10 29 16 -12 147 33 57 145 28 19 148 0 0 145 1 19 1.53
145 6 1 -44 0 0 10 30 30 30 18 -12 146 8 33 144 2 31 146 34 41 143 35 25 1.53
143 38 12 -43 0 0 10 30 50 31 20 -11 144 41 3 142 34 20 145 7 17 142 7 4 1.53
142 7 56 -42 0 0 10 31 12 31 21 -11 143 11 14 141 3 33 143 37 38 140 36 3 1.53
140 34 56 -41 0 0 10 31 34 32 23 -10 141 38 50 139 29 53 142 5 28 139 2 4 1.53
138 58 56 -40 0 0 10 31 57 32 25 -10 140 3 36 137 53 2 140 30 32 137 24 49 1.53
137 19 35 -39 0 0 10 32 21 33 27 -9 138 25 12 136 12 36 138 52 31 135 43 54 1.53
135 36 27 -38 0 0 10 32 46 33 29 -8 136 43 17 134 28 9 137 11 3 133 58 51 1.53
133 49 5 -37 0 0 10 33 12 33 31 -7 134 57 22 132 39 9 135 25 43 132 9 7 1.53
131 56 52 -36 0 0 10 33 39 33 33 -6 133 6 56 130 44 56 133 35 59 130 13 59 1.53
129 59 2 -35 0 0 10 34 7 33 35 -5 131 11 18 128 44 40 131 41 12 128 12 35 1.53
127 54 40 -34 0 0 10 34 37 33 38 -4 129 9 38 126 37 14 129 40 36 126 3 46 1.53
Latitude Latitude Latitude Latitude
126 0 0 -33 7 44 10 35 4 33 40 -3 -32 32 55 -33 43 9 -32 18 24 -33 58 18 1.53
125 0 0 -32 41 32 10 35 18 33 41 -2 -32 7 0 -33 16 41 -31 52 36 -33 31 42 1.52
124 0 0 -32 16 9 10 35 32 32 42 -1 -31 41 52 -32 51 1 -31 27 35 -33 5 55 1.52
123 0 0 -31 51 34 10 35 45 32 43 -1 -31 17 32 -32 26 10 -31 3 21 -32 40 58 1.52
122 0 0 -31 27 47 10 35 59 32 44 0 -30 53 59 -32 2 8 -30 39 53 -32 16 49 1.52
121 0 0 -31 4 48 10 36 12 32 45 1 -30 31 14 -31 38 55 -30 17 14 -31 53 30 1.52
120 0 0 -30 42 37 10 36 26 31 46 1 -30 9 16 -31 16 31 -29 55 21 -31 30 59 1.52
119 0 0 -30 21 14 10 36 39 31 47 2 -29 48 6 -30 54 55 -29 34 16 -31 9 18 1.52
118 0 0 -30 0 40 10 36 52 31 48 3 -29 27 43 -30 34 9 -29 13 57 -30 48 26 1.52
117 0 0 -29 40 54 10 37 5 30 49 3 -29 8 8 -30 14 11 -28 54 27 -30 28 23 1.52
116 0 0 -29 21 56 10 37 17 30 50 4 -28 49 20 -29 55 2 -28 35 43 -30 9 9 1.52
115 0 0 -29 3 46 10 37 30 29 51 5 -28 31 20 -29 36 42 -28 17 47 -29 50 45 1.52
114 0 0 -28 46 24 10 37 42 29 52 6 -28 14 8 -29 19 10 -28 0 39 -29 33 9 1.52
113 0 0 -28 29 51 10 37 54 28 52 7 -27 57 43 -29 2 28 -27 44 18 -29 16 23 1.52
112 0 0 -28 14 6 10 38 6 28 53 7 -27 42 7 -28 46 35 -27 28 45 -29 0 26 1.52
Uncertainty in time = +/- 2 secs
Prediction of 2018 Jan 17.0
Use these links for further information:
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[Observing Details]
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