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Updated: 2018 NOV 24, 06:00 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 2019 Jan 12 UT, the 93.5 km diameter asteroid (674) Rachele will occult a 10.5 mag star in the constellation Pisces for observers along a path across northern Australia from Geraldton across inland north-western Western Australia, central Northern Territory and into northern Queensland at decreasing elevation.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.00 mag to 12.26 mag (the magnitude of the asteroid) for at most 5.9 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
108 51 36 -36 0 0 13 55 22 30 307 -19 110 8 17 107 37 11 110 33 31 107 13 38 1.75
109 41 39 -35 0 0 13 55 30 30 306 -20 110 59 0 108 26 40 111 24 29 108 2 57 1.76
110 34 16 -34 0 0 13 55 39 30 304 -21 111 52 28 109 18 33 112 18 16 108 54 38 1.76
111 29 37 -33 0 0 13 55 48 29 303 -23 112 48 53 110 13 0 113 15 4 109 48 49 1.76
112 27 55 -32 0 0 13 55 57 29 302 -24 113 48 30 111 10 11 114 15 9 110 45 41 1.77
113 29 25 -31 0 0 13 56 7 29 301 -25 114 51 35 112 10 20 115 18 48 111 45 25 1.77
114 34 26 -30 0 0 13 56 16 29 299 -27 115 58 31 113 13 42 116 26 25 112 48 19 1.78
115 43 19 -29 0 0 13 56 26 28 298 -28 117 9 44 114 20 37 117 38 28 113 54 39 1.78
116 56 33 -28 0 0 13 56 36 28 297 -30 118 25 47 115 31 28 118 55 33 115 4 49 1.78
118 14 43 -27 0 0 13 56 46 27 295 -31 119 47 24 116 46 45 120 18 26 116 19 16 1.79
119 38 35 -26 0 0 13 56 57 26 294 -33 121 15 32 118 7 5 121 48 8 117 38 36 1.80
121 9 8 -25 0 0 13 57 7 25 292 -34 122 51 29 119 33 15 123 26 6 119 3 32 1.80
122 47 45 -24 0 0 13 57 18 24 291 -36 124 37 5 121 6 20 125 14 23 120 35 4 1.81
124 36 24 -23 0 0 13 57 30 23 290 -38 126 35 9 122 47 48 127 16 8 122 14 33 1.82
126 38 5 -22 0 0 13 57 41 22 288 -40 128 50 13 124 39 44 129 36 43 124 3 53 1.83
Latitude Latitude Latitude Latitude
127 0 0 -21 49 58 13 57 43 21 288 -40 -22 48 17 -20 53 32 -23 7 31 -20 35 42 1.79
128 0 0 -21 23 42 13 57 49 21 287 -41 -22 21 16 -20 27 56 -22 40 14 -20 10 19 1.81
129 0 0 -20 59 7 13 57 54 20 287 -42 -21 56 0 -20 3 59 -22 14 44 -19 46 33 1.81
130 0 0 -20 36 12 13 57 59 19 286 -42 -21 32 27 -19 41 38 -21 50 59 -19 24 22 1.81
131 0 0 -20 14 55 13 58 3 18 286 -43 -21 10 36 -19 20 52 -21 28 56 -19 3 46 1.81
132 0 0 -19 55 13 13 58 8 17 285 -44 -20 50 23 -19 1 40 -21 8 32 -18 44 42 1.81
133 0 0 -19 37 6 13 58 12 17 285 -45 -20 31 47 -18 43 59 -20 49 46 -18 27 10 1.82
134 0 0 -19 20 32 13 58 16 16 284 -45 -20 14 47 -18 27 48 -20 32 37 -18 11 6 1.82
135 0 0 -19 5 28 13 58 20 15 284 -46 -19 59 20 -18 13 6 -20 17 2 -17 56 31 1.82
136 0 0 -18 51 55 13 58 23 14 283 -47 -19 45 25 -17 59 52 -20 3 0 -17 43 23 1.82
137 0 0 -18 39 50 13 58 26 13 283 -47 -19 33 2 -17 48 5 -19 50 31 -17 31 41 1.83
138 0 0 -18 29 13 13 58 29 12 282 -48 -19 22 9 -17 37 43 -19 39 32 -17 21 24 1.83
139 0 0 -18 20 3 13 58 32 11 282 -48 -19 12 44 -17 28 47 -19 30 2 -17 12 31 1.83
140 0 0 -18 12 19 13 58 35 10 282 -48 -19 4 48 -17 21 14 -19 22 2 -17 5 2 1.84
141 0 0 -18 6 1 13 58 37 9 281 -49 -18 58 18 -17 15 5 -19 15 29 -16 58 56 1.85
142 0 0 -18 1 6 13 58 39 8 281 -49 -18 53 16 -17 10 18 -19 10 23 -16 54 12 1.85
143 0 0 -17 57 36 13 58 41 8 281 -49 -18 49 39 -17 6 54 -19 6 44 -16 50 50 1.87
144 0 0 -17 55 30 13 58 43 7 280 -50 -18 47 28 -17 4 52 -19 4 32 -16 48 49 1.88
145 0 0 -17 54 47 13 58 44 6 280 -50 -18 46 42 -17 4 12 -19 3 45 -16 48 9 1.90
146 0 0 -17 55 26 13 58 45 5 280 -50 -18 47 21 -17 4 52 -19 4 23 -16 48 50 1.92
147 0 0 -17 57 29 13 58 46 4 279 -50 -18 49 24 -17 6 54 -19 6 27 -16 50 52 1.96
148 0 0 -18 0 54 13 58 47 3 279 -50 -18 52 52 -17 10 17 -19 9 56 -16 54 14 2.03
149 0 0 -18 5 42 13 58 48 2 279 -50 -18 57 45 -17 15 0 -19 14 50 .. .. .. 2.17
150 0 0 -18 11 53 13 58 48 1 278 -50 -19 4 2 -17 21 5 -19 21 9 .. .. .. 2.63
151 0 0 .. .. .. .. .. .. .. .. .. .. .. .. -17 28 31 .. .. .. .. .. .. ....
Uncertainty in time = +/- 2 secs
Prediction of 2018 Nov 24.0
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