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Updated: 2015 OCT 02, 22:16 UT
Event Rank : 96
(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 Nov 30 UT, the 42 km diameter asteroid (678) Fredegundis will occult a 12.4 mag star in the constellation Taurus for observers along a path beginning near St Lawrence in Queensland. The path moves south-west passing near Emerald, and then into SA near Streaky Bay.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.3 mag to 11.0 mag (the magnitude of the asteroid) for at most 5.4 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: 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 48 56 -34 0 0 14 24 55 28 3 -34 133 19 30 134 18 33 132 55 30 134 43 0
134 58 1 -33 0 0 14 24 41 29 2 -35 134 28 27 135 27 48 134 4 21 135 52 23
136 8 51 -32 0 0 14 24 26 30 1 -36 135 39 6 136 38 50 135 14 52 137 3 34
137 21 34 -31 0 0 14 24 10 31 360 -37 136 51 35 137 51 47 136 27 10 138 16 44
138 36 18 -30 0 0 14 23 53 32 359 -38 138 6 2 139 6 48 137 41 24 139 32 0
139 53 14 -29 0 0 14 23 36 33 357 -39 139 22 38 140 24 5 138 57 44 140 49 35
141 12 33 -28 0 0 14 23 18 34 356 -40 140 41 34 141 43 50 140 16 21 142 9 41
142 34 30 -27 0 0 14 22 59 35 354 -41 142 3 3 143 6 16 141 37 28 143 32 32
143 59 19 -26 0 0 14 22 39 36 353 -42 143 27 19 144 31 39 143 1 18 144 58 25
145 27 19 -25 0 0 14 22 18 37 351 -43 144 54 40 146 0 19 144 28 10 146 27 39
146 58 50 -24 0 0 14 21 56 38 350 -44 146 25 27 147 32 37 145 58 21 148 0 38
148 34 19 -23 0 0 14 21 33 38 348 -45 148 0 3 149 9 1 147 32 16 149 37 49
150 14 15 -22 0 0 14 21 9 39 346 -46 149 38 58 150 50 3 149 10 22 151 19 46
151 59 18 -21 0 0 14 20 43 39 344 -46 151 22 46 152 36 22 150 53 13 153 7 13
153 50 13 -20 0 0 14 20 16 40 342 -47 153 12 14 154 28 51 152 41 32 155 1 2
155 48 4 -19 0 0 14 19 48 40 340 -47 155 8 17 156 28 36 154 36 12 157 2 26
157 54 11 -18 0 0 14 19 17 40 337 -48 157 12 12 158 37 6 156 38 25 159 13 1
Uncertainty in time = +/- 4 secs
Prediction of 2015 Oct 2.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
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