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Updated: 2008 OCT 30, 14:31 UT
Event Rank : 99
(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 2008 Nov 11 UT, the 195 km diameter asteroid (702) Alauda will occult a 12.0 mag star in the constellation Andromeda for observers along a very broad path across Australia from Townsville (from Ingham to Bowen) in Queensland across western New South Wales to Portland in Victoria, including from Warnambool to Kingston SE in South Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.9 mag to 12.2 mag (the magnitude of the asteroid) for at most 14.5 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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
142 10 13 -46 0 0 13 44 9 4 345 -26 139 55 48 144 30 49 139 8 45 145 23 10
141 57 17 -45 0 0 13 44 8 5 345 -27 139 45 42 144 14 46 138 59 36 145 5 54
141 47 3 -44 0 0 13 44 7 6 345 -28 139 38 2 144 1 42 138 52 48 144 51 43
141 39 21 -43 0 0 13 44 5 7 345 -29 139 32 40 143 51 24 138 48 14 144 40 25
141 34 0 -42 0 0 13 44 3 8 345 -30 139 29 29 143 43 42 138 45 47 144 31 50
141 30 55 -41 0 0 13 44 1 9 345 -31 139 28 22 143 38 29 138 45 20 144 25 47
141 29 59 -40 0 0 13 43 59 10 345 -32 139 29 13 143 35 36 138 46 48 144 22 9
141 31 6 -39 0 0 13 43 56 11 345 -33 139 31 58 143 34 56 138 50 7 144 20 49
141 34 10 -38 0 0 13 43 53 12 345 -34 139 36 32 143 36 24 138 55 11 144 21 41
141 39 8 -37 0 0 13 43 50 13 345 -35 139 42 51 143 39 56 139 1 58 144 24 39
141 45 56 -36 0 0 13 43 47 14 345 -36 139 50 51 143 45 26 139 10 24 144 29 40
141 54 31 -35 0 0 13 43 43 15 345 -37 140 0 31 143 52 51 139 20 26 144 36 39
142 4 49 -34 0 0 13 43 39 16 344 -38 140 11 47 144 2 8 139 32 3 144 45 33
142 16 49 -33 0 0 13 43 35 17 344 -39 140 24 38 144 13 15 139 45 12 144 56 20
142 30 28 -32 0 0 13 43 31 17 344 -40 140 39 2 144 26 8 139 59 51 145 8 56
142 45 46 -31 0 0 13 43 26 18 344 -41 140 54 58 144 40 48 140 16 1 145 23 22
143 2 42 -30 0 0 13 43 22 19 343 -42 141 12 25 144 57 12 140 33 38 145 39 34
143 21 14 -29 0 0 13 43 17 20 343 -43 141 31 22 145 15 20 140 52 45 145 57 34
143 41 23 -28 0 0 13 43 11 21 343 -44 141 51 49 145 35 11 141 13 19 146 17 20
144 3 8 -27 0 0 13 43 6 22 342 -45 142 13 46 145 56 47 141 35 21 146 38 52
144 26 30 -26 0 0 13 43 0 23 342 -46 142 37 14 146 20 6 141 58 52 147 2 11
144 51 30 -25 0 0 13 42 54 24 341 -47 143 2 14 146 45 11 142 23 51 147 27 19
145 18 10 -24 0 0 13 42 48 24 341 -48 143 28 46 147 12 3 142 50 22 147 54 17
145 46 31 -23 0 0 13 42 41 25 340 -49 143 56 52 147 40 44 143 18 24 148 23 6
146 16 34 -22 0 0 13 42 34 26 340 -50 144 26 34 148 11 16 143 47 59 148 53 51
146 48 24 -21 0 0 13 42 27 27 339 -51 144 57 54 148 43 42 144 19 11 149 26 33
147 22 2 -20 0 0 13 42 20 28 339 -52 145 30 56 149 18 7 144 52 0 150 1 17
147 57 34 -19 0 0 13 42 12 28 338 -53 146 5 41 149 54 35 145 26 31 150 38 9
148 35 2 -18 0 0 13 42 4 29 337 -54 146 42 14 150 33 11 146 2 47 151 17 12
Uncertainty in time = +/- 3 secs
[Prediction of 2008 Oct 30.0]
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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