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Updated: 2015 Mar 20, 03:08 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 2015 Apr 05 UT, the 168 km diameter asteroid (185) Eunike will occult a 12.1 mag star in the constellation Hercules for observers along a path across the south-western corner of the South Island of New Zealand.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.2 mag to 12.8 mag (the magnitude of the asteroid) for at most 15.0 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: .
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 TYC 0961-01875-1 by 185 Eunike on 2015 Apr 5
Centre Star Star Sun Path Limits Error Limits
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
166 19 31 -47 0 0 15 33 56 33 20 -37 167 28 44 165 9 52 167 49 26 164 48 53
166 34 40 -46 0 0 15 34 2 34 20 -38 167 42 33 165 26 23 168 2 50 165 5 49
166 48 49 -45 0 0 15 34 8 35 20 -38 167 55 26 165 41 50 168 15 20 165 21 39
167 2 3 -44 0 0 15 34 14 36 20 -39 168 7 27 165 56 17 168 27 1 165 36 28
167 14 24 -43 0 0 15 34 20 37 20 -39 168 18 40 166 9 47 168 37 53 165 50 20
167 25 56 -42 0 0 15 34 26 38 20 -39 168 29 8 166 22 25 168 48 2 166 3 17
167 36 42 -41 0 0 15 34 33 39 20 -40 168 38 52 166 34 13 168 57 28 166 15 24
Uncertainty in time = +/- 2 secs
Prediction of 2015 Mar 20.0
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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