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Updated: 2010 JUN 26, 05:09 UT
Event Rank : 95
(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 Aug 21 UT, the 108 km diameter asteroid (37) Fides will occult a 11.4 mag star in the constellation Taurus for observers along a path across south-east Victoria, and north-west Tasmania.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.9 mag to 11.7 mag (the magnitude of the asteroid) for at most 5.3 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 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
133 42 18 -47 0 0 19 54 49 20 16 -21 135 37 31 131 49 50 137 19 2 130 15 3
135 20 9 -46 0 0 19 54 54 21 14 -20 137 15 45 133 27 28 138 57 48 131 52 39
136 59 58 -45 0 0 19 54 59 22 13 -19 138 56 15 135 6 48 140 39 5 133 31 43
138 42 2 -44 0 0 19 55 5 24 11 -18 140 39 20 136 48 6 142 23 18 135 12 32
140 26 42 -43 0 0 19 55 12 25 9 -16 142 25 24 138 31 41 144 10 51 136 55 23
142 14 23 -42 0 0 19 55 19 26 8 -15 144 14 54 140 17 55 146 2 16 138 40 35
144 5 33 -41 0 0 19 55 26 27 6 -14 146 8 24 142 7 12 147 58 11 140 28 32
146 0 46 -40 0 0 19 55 34 28 4 -12 148 6 32 144 0 1 149 59 22 142 19 39
148 0 43 -39 0 0 19 55 43 29 2 -10 150 10 10 145 56 58 152 6 51 144 14 27
150 6 16 -38 0 0 19 55 52 30 359 -9 152 20 20 147 58 46 154 21 56 146 13 34
Latitude Latitude Latitude Latitude
151 0 0 -37 35 13 19 55 57 31 358 -8 -38 36 38 -36 35 38 -39 31 4 -35 45 42
152 0 0 -37 8 12 19 56 1 31 357 -7 -38 9 9 -36 9 2 -39 3 9 -35 19 27
153 0 0 -36 41 53 19 56 6 32 356 -6 -37 42 23 -35 43 7 -38 35 57 -34 53 51
154 0 0 -36 16 15 19 56 11 32 355 -5 -37 16 19 -35 17 53 -38 9 29 -34 28 57
155 0 0 -35 51 20 19 56 15 32 354 -4 -36 51 0 -34 53 22 -37 43 46 -34 4 43
Uncertainty in time = +/- 3 secs
Prediction of 2010 Jun 26.0
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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