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Updated: 2010 AUG 10, 00:43 UT
Event Rank : 63
(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 2010 Oct 02 UT, the 141 km diameter Jupiter Trojan binary asteroid (617) Patroclus will occult a 10.5 mag star in the constellation Scorpius for observers along a wide, large uncertainty path across New Zealand. The centreline lies approximately over Hokianga Harbour, but a path shift to anywhere over New Zealand is possible. Note that this minor planet has a large satellite, Menoetius.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.3 mag to 15.8 mag (the magnitude of the asteroid) for at most 7.2 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC.
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
E. Longitude Latitude U.T. Alt Az Alt
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
164 41 47 -46 43 23 11 58 23 30 240 -38 163 10 52 -46 52 7 166 14 40 -46 32 24 160 19 55 -47 3 15 169 20 56 -46 3 57
165 41 50 -45 18 58 11 58 29 29 239 -40 164 11 13 -45 29 24 167 14 33 -45 6 8 161 21 3 -45 43 30 170 20 56 -44 33 30
166 44 38 -43 51 24 11 58 35 27 237 -42 165 14 0 -44 3 47 168 17 33 -43 36 26 162 24 7 -44 21 12 171 24 58 -42 58 53
167 50 49 -42 20 6 11 58 41 26 236 -43 166 19 45 -42 34 44 169 24 22 -42 2 36 163 29 33 -42 55 57 172 33 59 -41 19 8
169 1 9 -40 44 18 11 58 47 24 235 -45 167 29 11 -41 1 37 170 35 57 -40 23 45 164 37 53 -41 27 16 173 49 20 -39 32 53
170 16 44 -39 2 56 11 58 53 23 234 -47 168 43 11 -39 23 32 171 53 36 -38 38 35 165 49 49 -39 54 28 175 13 6 -37 38 7
171 39 8 -37 14 28 11 58 59 21 233 -49 170 3 4 -37 39 14 173 19 17 -36 45 9 167 6 18 -38 16 39 176 48 40 -35 31 29
173 10 47 -35 16 33 11 59 5 18 232 -51 171 30 44 -35 46 52 174 56 13 -34 40 21 168 28 37 -36 32 36 178 42 28 -33 6 39
174 55 50 -33 5 9 11 59 11 16 230 -53 173 9 16 -33 43 27 176 50 19 -32 18 25 169 58 43 -34 40 27 -178 50 1 -30 8 32
Uncertainty in time = +/- 12 secs
Prediction of 2010 Jul 12.0
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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