|
|
Updated: 2009 JAN 22, 17:38 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 2009 Jan 25 UT, the 86 km diameter asteroid (980) Anacostia will occult a 10.1 mag star in the constellation Taurus for observers along a path across southern Queensland and central South Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.4 mag to 12.3 mag (the magnitude of the asteroid) for at most 9.7 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
126 55 6 -37 0 0 15 27 32 19 326 -34 125 17 2 128 39 14 123 58 36 130 12 25
127 50 13 -36 0 0 15 27 18 20 326 -35 126 10 21 129 36 39 124 50 42 131 12 18
128 50 14 -35 0 0 15 27 2 20 325 -36 127 8 5 130 39 35 125 46 52 132 18 25
129 55 38 -34 0 0 15 26 46 21 323 -37 128 10 36 131 48 44 126 47 25 133 31 39
131 7 6 -33 0 0 15 26 30 21 322 -38 129 18 26 133 4 59 127 52 48 134 53 17
132 25 33 -32 0 0 15 26 12 21 321 -39 130 32 15 134 29 39 129 3 34 136 25 8
133 52 15 -31 0 0 15 25 52 21 320 -40 131 52 59 136 4 37 130 20 25 138 10 7
135 29 5 -30 0 0 15 25 32 21 318 -41 133 21 55 137 52 54 131 44 20 140 13 14
137 18 53 -29 0 0 15 25 9 21 317 -42 135 0 52 139 59 37 133 16 43 142 44 36
139 26 36 -28 0 0 15 24 44 20 315 -43 136 52 43 142 35 12 134 59 31 146 12 36
140 0 0 -27 45 56 15 24 38 20 315 -43 -26 36 21 -28 59 50 -25 40 42 -30 5 57
141 0 0 -27 22 17 15 24 27 20 314 -43 -26 13 41 -28 35 0 -25 18 46 -29 39 54
142 0 0 -27 0 39 15 24 16 19 313 -43 -25 52 55 -28 12 19 -24 58 38 -29 16 11
143 0 0 -26 40 59 15 24 6 19 313 -43 -25 34 2 -27 51 45 -24 40 18 -28 54 42
144 0 0 -26 23 14 15 23 56 18 312 -43 -25 16 57 -27 33 12 -24 23 43 -28 35 22
145 0 0 -26 7 22 15 23 46 18 311 -43 -25 1 40 -27 16 39 -24 8 52 -28 18 7
146 0 0 -25 53 20 15 23 37 17 311 -43 -24 48 8 -27 2 2 -23 55 42 -28 2 56
147 0 0 -25 41 8 15 23 27 17 310 -43 -24 36 21 -26 49 20 -23 44 13 -27 49 45
148 0 0 -25 30 42 15 23 18 16 309 -43 -24 26 16 -26 38 31 -23 34 23 -27 38 32
149 0 0 -25 22 4 15 23 10 16 309 -43 -24 17 54 -26 29 34 -23 26 13 -27 29 16
150 0 0 -25 15 11 15 23 2 15 308 -43 -24 11 13 -26 22 27 -23 19 41 -27 21 55
151 0 0 -25 10 3 15 22 54 14 308 -43 -24 6 13 -26 17 10 -23 14 47 -27 16 29
152 0 0 -25 6 40 15 22 46 14 307 -42 -24 2 54 -26 13 43 -23 11 30 -27 12 58
153 0 0 -25 5 3 15 22 39 13 306 -42 -24 1 16 -26 12 5 -23 9 52 -27 11 21
154 0 0 -25 5 10 15 22 32 12 306 -41 -24 1 19 -26 12 18 -23 9 52 -27 11 38
155 0 0 -25 7 3 15 22 26 12 305 -41 -24 3 3 -26 14 20 -23 11 30 -27 13 50
Uncertainty in time = +/- 4 secs
[Prediction of 2009 Jan 23.0]
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
[Asteroid Occultation Results]
[Top of Page][Return to Home Page]