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Updated: 2014 NOV 12, 11:54 UT
Event Rank : 100
(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 2014 Dec 18 UT, the 219 km diameter asteroid (702) Alauda will occult a 6.2 mag star in the constellation Perseus for observers along a very broad path across eastern Australia, including much of eastern Queensland and New South Wales. Brisbane is just east of the path, Sydney and Canberra are included, but at low elevation
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.2 mag to 12.4 mag (the magnitude of the asteroid) for at most 17.1 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: .
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
153 0 37 -38 0 0 14 15 55 1 324 -28 149 29 31 ... .. .. 148 42 49 ... .. ..
152 12 23 -37 0 0 14 15 54 2 324 -29 148 50 3 156 8 17 148 5 3 ... .. ..
151 30 19 -36 0 0 14 15 53 3 325 -30 148 15 27 155 14 52 147 31 53 156 15 5
150 53 42 -35 0 0 14 15 52 4 325 -32 147 45 14 154 28 50 147 2 56 155 26 1
150 21 58 -34 0 0 14 15 50 6 325 -33 147 19 1 153 49 11 146 37 49 154 43 52
149 54 38 -33 0 0 14 15 47 7 325 -34 146 56 29 153 15 8 146 16 16 154 7 45
149 31 21 -32 0 0 14 15 45 8 326 -35 146 37 23 152 46 8 145 58 1 153 37 0
149 11 48 -31 0 0 14 15 42 9 326 -36 146 21 28 152 21 41 145 42 51 153 11 5
148 55 45 -30 0 0 14 15 38 10 326 -37 146 8 35 152 1 24 145 30 37 152 49 33
148 42 57 -29 0 0 14 15 35 11 326 -38 145 58 33 151 45 1 145 21 10 152 32 6
148 33 15 -28 0 0 14 15 31 11 326 -39 145 51 13 151 32 14 145 14 20 152 18 27
148 26 30 -27 0 0 14 15 26 12 326 -40 145 46 30 151 22 53 145 10 3 152 8 21
148 22 34 -26 0 0 14 15 22 13 326 -41 145 44 18 151 16 48 145 8 13 152 1 39
148 21 22 -25 0 0 14 15 17 14 326 -42 145 44 31 151 13 50 145 8 44 151 58 11
148 22 48 -24 0 0 14 15 12 15 325 -43 145 47 6 151 13 54 145 11 34 151 57 52
148 26 50 -23 0 0 14 15 6 16 325 -44 145 52 1 151 16 54 145 16 40 152 0 35
148 33 25 -22 0 0 14 15 1 16 325 -45 145 59 12 151 22 47 145 24 0 152 6 18
148 42 30 -21 0 0 14 14 55 17 325 -46 146 8 38 151 31 32 145 33 32 152 14 59
148 54 5 -20 0 0 14 14 48 18 325 -47 146 20 20 151 43 8 145 45 15 152 26 36
149 8 11 -19 0 0 14 14 42 19 324 -48 146 34 16 151 57 35 145 59 10 152 41 11
149 24 49 -18 0 0 14 14 35 19 324 -49 146 50 27 152 14 56 146 15 17 152 58 45
149 44 0 -17 0 0 14 14 27 20 324 -49 147 8 56 152 35 13 146 33 38 153 19 23
150 5 48 -16 0 0 14 14 20 20 323 -50 147 29 44 152 58 31 146 54 14 153 43 10
Uncertainty in time = +/- 2 secs
Prediction of 2014 Nov 12.0
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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