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Updated: 2017 JUN 10, 20:15 UT
Event Rank : 92
(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 01 UT, the 74 km diameter asteroid (516) Amherstia will occult a 10.5 mag star in the constellation Pisces for observers along a south-to-north path across eastern WA passing over the Nullarbor and Halls Creek.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.24 mag to 13.70 mag (the magnitude of the asteroid) for at most 11.2 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 Limit1 Path Limit2 Error Limit1 Error Limit2 Alt
E. Longitude Latitude U.T. Alt Az Alt Crn
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
127 8 7 -33 56 9 19 15 3 41 10 -39 126 43 47 -33 57 4 127 32 25 -33 55 17 126 24 17 -33 57 51 127 51 50 -33 54 38 -0.15
127 13 59 -31 47 4 19 15 27 43 10 -39 126 50 15 -31 47 56 127 37 41 -31 46 16 126 31 14 -31 48 39 127 56 37 -31 45 40 -0.15
127 18 18 -29 42 59 19 15 51 45 10 -39 126 55 5 -29 43 47 127 41 29 -29 42 14 126 36 30 -29 44 28 128 0 0 -29 41 40 -0.15
127 21 21 -27 43 10 19 16 15 47 10 -39 126 58 35 -27 43 56 127 44 4 -27 42 28 126 40 22 -27 44 34 128 2 14 -27 41 56 -0.15
127 23 19 -25 47 6 19 16 39 49 10 -39 127 0 57 -25 47 49 127 45 39 -25 46 26 126 43 3 -25 48 26 128 3 30 -25 45 55 -0.15
127 24 22 -23 54 19 19 17 3 51 11 -38 127 2 21 -23 55 0 127 46 21 -23 53 40 126 44 43 -23 55 35 128 3 56 -23 53 12 -0.15
127 24 37 -22 4 26 19 17 26 52 11 -38 127 2 54 -22 5 6 127 46 18 -22 3 50 126 45 31 -22 5 39 128 3 38 -22 3 22 -0.15
127 24 11 -20 17 9 19 17 50 54 11 -38 127 2 44 -20 17 47 127 45 36 -20 16 34 126 45 34 -20 18 19 128 2 43 -20 16 7 0.14
127 23 7 -18 32 11 19 18 14 56 12 -38 127 1 55 -18 32 48 127 44 18 -18 31 37 126 44 56 -18 33 19 128 1 15 -18 31 11 0.14
127 21 31 -16 49 18 19 18 38 58 12 -37 127 0 31 -16 49 53 127 42 30 -16 48 45 126 43 42 -16 50 23 127 59 16 -16 48 20 0.14
127 19 25 -15 8 17 19 19 2 59 13 -37 126 58 36 -15 8 52 127 40 13 -15 7 45 126 41 56 -15 9 21 127 56 51 -15 7 21 0.14
127 16 52 -13 28 58 19 19 26 61 13 -36 126 56 13 -13 29 31 127 37 31 -13 28 27 126 39 40 -13 30 0 127 54 1 -13 28 3 0.14
127 13 55 -11 51 11 19 19 50 62 14 -36 126 53 23 -11 51 44 127 34 25 -11 50 40 126 36 57 -11 52 11 127 50 49 -11 50 17 0.14
127 10 35 -10 14 47 19 20 14 64 14 -36 126 50 10 -10 15 19 127 30 58 -10 14 17 126 33 50 -10 15 46 127 47 17 -10 13 55 0.14
Uncertainty in time = +/- 5 secs
Prediction of 2017 Jun 10.0
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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