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Updated: 2007 APR 14, 00:09 UT
Event Rank : 21
(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 2007 May 13 UT, the 36 km diameter asteroid (1499) Pori will occult a 11.5 mag star in the constellation Ophiuchus for observers along a path across New Zealand beginning over Masterton in the North Island, then Wanganui and New Plymouth. This event has a wide area of uncertainty extending from Auckland in the north to Nelson in the south.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.1 mag to 14.5 mag (the magnitude of the asteroid) for at most 4.3 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
176 21 48 -41 56 25 10 21 17 41 81 -57 176 3 1 -42 0 48 176 40 26 -41 52 0 174 2 14 -42 27 16 178 34 5 -41 23 29
175 39 56 -41 2 55 10 21 30 41 82 -57 175 21 18 -41 7 13 175 58 27 -40 58 36 173 21 24 -41 33 4 177 51 17 -40 30 40
174 57 29 -40 9 22 10 21 43 40 84 -57 174 38 58 -40 13 34 175 15 52 -40 5 9 172 39 51 -40 38 49 177 8 0 -39 37 48
174 14 22 -39 15 44 10 21 56 40 85 -57 173 55 57 -39 19 50 174 32 39 -39 11 36 171 57 30 -39 44 27 176 24 10 -38 44 51
173 30 33 -38 21 59 10 22 9 39 86 -57 173 12 13 -38 25 59 173 48 44 -38 17 57 171 14 18 -38 49 58 175 39 44 -37 51 48
172 45 58 -37 28 5 10 22 22 39 87 -57 172 27 42 -37 31 59 173 4 5 -37 24 9 170 30 13 -37 55 19 174 54 40 -36 58 36
172 0 34 -36 34 1 10 22 35 38 88 -57 171 42 21 -36 37 48 172 18 38 -36 30 11 169 45 11 -37 0 28 174 8 53 -36 5 15
171 14 17 -35 39 43 10 22 48 38 89 -57 170 56 6 -35 43 24 171 32 19 -35 36 0 168 59 7 -36 5 23 173 22 21 -35 11 42
170 27 2 -34 45 11 10 23 1 37 91 -57 170 8 52 -34 48 45 170 45 4 -34 41 33 168 11 56 -35 10 1 172 34 59 -34 17 55
169 38 45 -33 50 20 10 23 14 36 92 -56 169 20 34 -33 53 48 169 56 47 -33 46 50 167 23 33 -34 14 20 171 46 42 -33 23 53
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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