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Updated: 2017 JUL 16, 23:51 UT
Event Rank : 100
(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 Aug 19 UT, the 453 km diameter asteroid (10) Hygiea will occult a 10.0 mag star in the constellation Sagittarius for observers along a wide path across eastern Australia, passing over Tasmania and coastal areas from Lakes Entrance to Gold Coast, including Sydney. Canberra is located within the 1-sigma uncertainty area.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.91 mag to 10.30 mag (the magnitude of the asteroid) for at most 343.8 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
157 44 12 -24 0 0 9 44 7 88 40 -35 160 5 8 155 22 12 160 16 22 155 10 47 -0.01
157 21 4 -25 0 0 9 42 22 87 39 -34 159 43 32 154 57 22 159 54 53 154 45 49 -0.02
156 57 1 -26 0 0 9 40 36 86 38 -33 159 21 8 154 31 30 159 32 37 154 19 47 -0.02
156 31 58 -27 0 0 9 38 50 85 39 -33 158 57 52 154 4 29 159 9 29 153 52 36 -0.03
156 5 49 -28 0 0 9 37 3 83 39 -32 158 33 39 153 36 13 158 45 25 153 24 10 -0.04
155 38 30 -29 0 0 9 35 17 82 39 -31 158 8 25 153 6 37 158 20 20 152 54 22 -0.04
155 9 55 -30 0 0 9 33 29 81 40 -30 157 42 4 152 35 33 157 54 9 152 23 5 -0.05
154 39 56 -31 0 0 9 31 42 80 40 -29 157 14 30 152 2 53 157 26 46 151 50 12 -0.05
154 8 27 -32 0 0 9 29 54 78 41 -28 156 45 37 151 28 30 156 58 5 151 15 34 -0.06
Latitude Latitude Latitude Latitude
153 0 0 -34 0 44 9 26 16 76 42 -27 -38 25 56 -29 13 1 -38 46 20 -28 48 52 -0.07
152 0 0 -35 36 49 9 23 21 74 43 -25 -39 48 51 -31 5 9 -40 8 18 -30 42 26 -0.08
151 0 0 -37 4 55 9 20 40 72 43 -24 -41 5 18 -32 47 26 -41 23 55 -32 25 58 -0.08
150 0 0 -38 26 0 9 18 12 70 44 -22 -42 16 1 -34 21 1 -42 33 53 -34 0 40 -0.09
149 0 0 -39 40 50 9 15 53 68 45 -21 -43 21 37 -35 46 57 -43 38 48 -35 27 35 -0.09
148 0 0 -40 50 8 9 13 45 66 46 -20 -44 22 38 -37 6 7 -44 39 12 -36 47 37 -0.10
147 0 0 -41 54 27 9 11 45 65 47 -19 -45 19 30 -38 19 15 -45 35 32 -38 1 31 -0.10
146 0 0 -42 54 19 9 9 52 63 48 -18 -46 12 38 -39 27 1 -46 28 10 -39 9 59 -0.10
145 0 0 -43 50 9 9 8 6 62 49 -17 -47 2 22 -40 29 58 -47 17 27 -40 13 33 -0.10
144 0 0 -44 42 20 9 6 27 61 50 -16 -47 49 0 -41 28 35 -48 3 40 -41 12 44 -0.10
143 0 0 -45 31 11 9 4 53 59 51 -15 -48 32 47 -42 23 16 -48 47 5 -42 7 55 -0.10
Uncertainty in time = +/- 18 secs
Prediction of 2017 Jul 16.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
[Asteroid Occultation Results]
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