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Updated: 2011 AUG 23, 00:18 UT
Event Rank : 85
(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 2011 Sep 07 UT, the 132 km diameter asteroid (200) Dynamene will occult a 13.3 mag star in the constellation Aries for observers along a path across New Zealand from Auckland down the eastern coast to Picturn, passing just east of Christchurch.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.4 mag to 12.4 mag (the magnitude of the asteroid) for at most 20.4 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 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
172 27 12 -53 0 0 16 45 30 12 352 -20 173 42 39 171 12 30 175 14 19 169 43 48
172 31 13 -52 0 0 16 45 35 13 352 -20 173 44 59 171 18 11 175 14 34 169 51 27
172 36 19 -51 0 0 16 45 40 14 352 -21 173 48 29 171 24 50 175 16 8 169 59 56
172 42 25 -50 0 0 16 45 45 15 352 -21 173 53 7 171 32 24 175 18 56 170 9 14
172 49 28 -49 0 0 16 45 51 16 352 -21 173 58 47 171 40 50 175 22 54 170 19 16
172 57 26 -48 0 0 16 45 58 17 352 -21 174 5 26 171 50 4 175 27 57 170 30 2
173 6 14 -47 0 0 16 46 5 18 351 -21 174 13 0 172 0 5 175 34 2 170 41 28
173 15 51 -46 0 0 16 46 12 19 351 -21 174 21 28 172 10 50 175 41 5 170 53 34
173 26 14 -45 0 0 16 46 19 20 351 -21 174 30 47 172 22 17 175 49 5 171 6 17
173 37 22 -44 0 0 16 46 27 21 351 -22 174 40 54 172 34 25 175 57 58 171 19 36
173 49 12 -43 0 0 16 46 35 22 350 -22 174 51 47 172 47 12 176 7 41 171 33 30
174 1 44 -42 0 0 16 46 44 23 350 -22 175 3 25 173 0 37 176 18 14 171 47 57
174 14 56 -41 0 0 16 46 53 24 350 -22 175 15 47 173 14 38 176 29 35 172 2 58
174 28 47 -40 0 0 16 47 2 25 349 -22 175 28 50 173 29 16 176 41 41 172 18 31
174 43 16 -39 0 0 16 47 12 26 349 -22 175 42 35 173 44 28 176 54 32 172 34 36
174 58 22 -38 0 0 16 47 22 27 349 -22 175 57 0 174 0 15 177 8 7 172 51 11
175 14 4 -37 0 0 16 47 32 27 348 -21 176 12 4 174 16 36 177 22 25 173 8 18
175 30 23 -36 0 0 16 47 43 28 348 -21 176 27 47 174 33 31 177 37 24 173 25 55
175 47 18 -35 0 0 16 47 54 29 347 -21 176 44 8 174 50 59 177 53 5 173 44 3
176 4 48 -34 0 0 16 48 5 30 347 -21 177 1 8 175 9 0 178 9 27 174 2 41
176 22 54 -33 0 0 16 48 17 31 346 -21 177 18 45 175 27 34 178 26 29 174 21 50
176 41 35 -32 0 0 16 48 29 32 346 -21 177 36 59 175 46 42 178 44 12 174 41 29
Uncertainty in time = +/- 12 secs
Prediction of 2011 Aug 23.0
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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