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Updated: 2008 FEB 27, 20:10 UT
Event Rank : 84
(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 Mar 10 UT, the 57 km diameter asteroid (255) Oppavia will occult a 11.6 mag star in the constellation Gemini for observers along a path across Australia from near Lismore in northern New South Wales, roughly parallel to the Queensland east coast to south of Weipa.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.5 mag to 15.1 mag (the magnitude of the asteroid) for at most 6.8 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
156 23 40 -35 0 0 11 12 43 15 334 -37 156 0 12 156 47 9 155 31 33 157 15 47
155 38 41 -34 0 0 11 12 39 16 334 -37 155 15 29 156 1 52 154 47 11 156 30 10
154 54 14 -33 0 0 11 12 34 17 335 -38 154 31 18 155 17 9 154 3 19 155 45 7
154 10 16 -32 0 0 11 12 29 18 335 -38 153 47 35 154 32 56 153 19 54 155 0 36
153 26 44 -31 0 0 11 12 24 20 335 -38 153 4 17 153 49 11 152 36 53 154 16 33
152 43 36 -30 0 0 11 12 18 21 336 -38 152 21 22 153 5 49 151 54 14 153 32 55
152 0 48 -29 0 0 11 12 12 22 336 -38 151 38 46 152 22 49 151 11 53 152 49 40
151 18 19 -28 0 0 11 12 5 23 337 -38 150 56 28 151 40 9 150 29 48 152 6 46
150 36 5 -27 0 0 11 11 59 24 337 -38 150 14 25 150 57 45 149 47 58 151 24 8
149 54 5 -26 0 0 11 11 52 25 338 -37 149 32 35 150 15 35 149 6 19 150 41 47
149 12 16 -25 0 0 11 11 44 27 338 -37 148 50 55 149 33 37 148 24 50 149 59 37
148 30 36 -24 0 0 11 11 36 28 339 -37 148 9 23 148 51 48 147 43 28 149 17 39
147 49 2 -23 0 0 11 11 28 29 339 -37 147 27 57 148 10 7 147 2 10 148 35 48
147 7 33 -22 0 0 11 11 20 30 339 -37 146 46 34 147 28 31 146 20 56 147 54 4
146 26 7 -21 0 0 11 11 11 31 340 -37 146 5 13 146 46 58 145 39 43 147 12 24
145 44 40 -20 0 0 11 11 3 33 340 -36 145 23 52 146 5 26 144 58 28 146 30 45
145 3 12 -19 0 0 11 10 53 34 341 -36 144 42 29 145 23 53 144 17 10 145 49 6
144 21 39 -18 0 0 11 10 44 35 341 -36 144 1 0 144 42 17 143 35 46 145 7 24
143 40 1 -17 0 0 11 10 34 36 342 -35 143 19 25 144 0 35 142 54 15 144 25 38
142 58 14 -16 0 0 11 10 23 37 342 -35 142 37 41 143 18 45 142 12 34 143 43 45
142 16 17 -15 0 0 11 10 13 38 343 -35 141 55 46 142 36 46 141 30 41 143 1 43
141 34 8 -14 0 0 11 10 2 40 343 -34 141 13 38 141 54 35 140 48 34 142 19 30
140 51 43 -13 0 0 11 9 51 41 344 -34 140 31 14 141 12 10 140 6 11 141 37 4
140 9 2 -12 0 0 11 9 39 42 344 -33 139 48 33 140 29 29 139 23 30 140 54 23
139 26 2 -11 0 0 11 9 27 43 345 -33 139 5 32 139 46 29 138 40 28 140 11 23
138 42 39 -10 0 0 11 9 15 44 345 -32 138 22 8 139 3 8 137 57 2 139 28 4
137 58 53 - 9 0 0 11 9 3 45 346 -31 137 38 19 138 19 24 137 13 11 138 44 22
137 14 40 - 8 0 0 11 8 50 46 347 -31 136 54 3 137 35 13 136 28 51 138 0 15
136 29 57 - 7 0 0 11 8 37 48 347 -30 136 9 17 136 50 34 135 44 0 137 15 40
135 44 43 - 6 0 0 11 8 23 49 348 -30 135 23 58 136 5 24 134 58 35 136 30 35
134 58 53 - 5 0 0 11 8 10 50 349 -29 134 38 3 135 19 40 134 12 34 135 44 56
134 12 25 - 4 0 0 11 7 56 51 350 -28 133 51 29 134 33 18 133 25 52 134 58 41
133 25 16 - 3 0 0 11 7 41 52 351 -27 133 4 13 133 46 16 132 38 27 134 11 47
132 37 22 - 2 0 0 11 7 26 53 352 -27 132 16 11 132 58 30 131 50 15 133 24 11
131 48 40 - 1 0 0 11 7 11 54 353 -26 131 27 20 132 9 56 131 1 13 132 35 48
130 59 6 0 0 0 11 6 56 55 354 -25 130 37 36 131 20 32 130 11 16 131 46 35
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
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[Asteroid Occultation Results]
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