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Updated: 2019 Jul 21, 06:43 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 Oct 14 UT, the 86 km diameter asteroid (983) Gunila will occult a 12.2 mag star in the constellation Taurus for observers along a path across northern Queensland, north-western South Australia and south-eastern West Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.95 mag to 15.06 mag (the magnitude of the asteroid) for at most 10.0 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.
Occultation of UCAC4-586-009776 by 983 Gunila on 2019 Oct 14
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
122 6 21 -37 0 0 16 49 14 23 20 -42 121 9 37 123 3 31 120 37 46 123 36 1 0.94
123 20 7 -36 0 0 16 49 4 24 19 -42 122 23 31 124 17 11 121 51 45 124 49 37 0.94
124 34 38 -35 0 0 16 48 54 26 18 -43 123 38 6 125 31 39 123 6 23 126 4 4 0.94
125 50 0 -34 0 0 16 48 43 27 17 -43 124 53 28 126 47 1 124 21 46 127 19 28 0.94
127 6 19 -33 0 0 16 48 31 28 16 -44 126 9 44 128 3 26 125 38 1 128 35 56 0.94
128 23 43 -32 0 0 16 48 19 29 15 -44 127 27 1 129 20 58 126 55 14 129 53 34 0.94
129 42 17 -31 0 0 16 48 6 30 14 -44 128 45 24 130 39 46 128 13 31 131 12 30 0.94
131 2 11 -30 0 0 16 47 52 32 13 -44 130 5 2 131 59 58 129 33 1 132 32 53 0.94
132 23 32 -29 0 0 16 47 38 33 12 -44 131 26 2 133 21 42 130 53 51 133 54 51 0.94
133 46 30 -28 0 0 16 47 23 34 10 -44 132 48 34 134 45 7 132 16 9 135 18 34 0.94
135 11 13 -27 0 0 16 47 7 35 9 -44 134 12 47 136 10 25 133 40 5 136 44 12 0.94
136 37 54 -26 0 0 16 46 51 36 8 -44 135 38 50 137 37 46 135 5 49 138 11 57 0.94
138 6 44 -25 0 0 16 46 34 38 6 -44 137 6 56 139 7 23 136 33 32 139 42 2 0.94
139 37 56 -24 0 0 16 46 16 39 5 -43 138 37 18 140 39 31 138 3 27 141 14 44 0.94
141 11 48 -23 0 0 16 45 57 40 3 -43 140 10 10 142 14 27 139 35 47 142 50 18 0.94
142 48 35 -22 0 0 16 45 37 41 1 -42 141 45 48 143 52 29 141 10 49 144 29 6 0.94
144 28 40 -21 0 0 16 45 16 42 359 -42 143 24 33 145 34 2 142 48 51 146 11 31 0.94
146 12 27 -20 0 0 16 44 54 43 357 -41 145 6 46 147 19 30 144 30 14 147 58 0 0.94
148 0 25 -19 0 0 16 44 31 44 355 -40 146 52 55 149 9 27 146 15 25 149 49 9 0.94
149 53 9 -18 0 0 16 44 7 45 353 -39 148 43 30 151 4 32 148 4 53 151 45 40 0.94
Uncertainty in time = +/- 4 secs
Prediction of 2019 Jul 21.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
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[Reporting Details]
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