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Updated: 2016 OCT 11, 03:57 UT
Event Rank : 52
(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 Sep 14 UT, the 22 km diameter asteroid (990) Yerkes will occult a 9.5 mag star in the constellation Scorpius for observers along a path near the North Island of New Zealand, possibly crossing Cape Reinga.
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.80 mag to 16.30 mag (the magnitude of the asteroid) for at most 1.5 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, 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 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
158 9 35 -49 27 57 12 59 5 29 253 -44 157 53 8 -49 27 52 158 26 7 -49 27 59 157 10 27 -49 27 23 159 9 52 -49 27 48 1.14
159 19 29 -48 21 36 12 59 12 28 252 -45 159 3 1 -48 21 46 159 36 3 -48 21 23 158 20 16 -48 21 55 160 19 54 -48 20 30 1.14
160 31 30 -47 13 19 12 59 19 27 251 -46 160 14 57 -47 13 46 160 48 9 -47 12 49 159 32 2 -47 14 37 161 32 14 -47 11 11 1.15
161 46 7 -46 2 48 12 59 26 26 249 -47 161 29 25 -46 3 33 162 2 54 -46 1 59 160 46 10 -46 5 12 162 47 23 -45 59 29 1.15
163 3 52 -44 49 40 12 59 33 24 248 -48 162 46 58 -44 50 47 163 20 53 -44 48 29 162 3 12 -44 53 20 164 5 59 -44 45 0 1.15
164 25 32 -43 33 26 12 59 40 23 247 -50 164 8 20 -43 34 57 164 42 51 -43 31 49 163 23 50 -43 38 33 165 28 50 -43 27 10 1.16
165 52 5 -42 13 24 12 59 47 22 245 -51 165 34 27 -42 15 25 166 9 51 -42 11 16 164 48 54 -42 20 16 166 57 5 -42 5 13 1.17
167 24 54 -40 48 38 12 59 54 20 244 -52 167 6 40 -40 51 17 167 43 18 -40 45 53 166 19 38 -40 57 40 168 32 20 -40 38 3 1.18
169 6 2 -39 17 46 13 0 1 18 243 -54 168 46 55 -39 21 13 169 25 21 -39 14 11 167 57 46 -39 29 34 170 17 0 -39 4 1 1.19
170 58 43 -37 38 34 13 0 8 16 241 -55 170 38 17 -37 43 6 171 19 26 -37 33 49 169 45 59 -37 54 8 172 15 8 -37 20 21 1.21
173 8 49 -35 47 2 13 0 15 13 240 -56 172 46 12 -35 53 16 173 31 52 -35 40 29 171 48 49 -36 8 17 174 34 31 -35 21 44 1.24
175 49 8 -33 34 29 13 0 22 10 238 -58 175 22 16 -33 43 49 176 16 53 -33 24 32 174 15 22 -34 5 50 177 34 35 -32 54 58 1.31
179 44 8 -30 30 51 13 0 29 6 236 -59 179 3 27 -30 49 46 -179 30 47 -30 8 57 177 30 17 -31 30 8 -176 44 32 -28 38 55 1.59
Uncertainty in time = +/- 3 secs
Prediction of 2016 Oct 11.0
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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