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Updated: 2011 JUL 02, 00:26 UT
Event Rank : 24
(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 2011 Aug 11 UT, the 35 km diameter asteroid (2291) Kevo will occult a 7.1 mag star in the constellation Ophiuchus for observers along a north-to-south path across Australia passing near Mt Isa, Adelaide and Mt Gambier.
In the case of an occultation, the combined light of the asteroid and the star will drop by 9.2 mag to 16.3 mag (the magnitude of the asteroid) for at most 2.9 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, 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
141 44 47 -42 0 0 13 17 8 33 318 -58 141 28 51 142 0 46 139 58 39 143 33 16
141 25 12 -41 0 0 13 17 1 34 318 -59 141 9 34 141 40 52 139 41 5 143 11 32
141 7 18 -40 0 0 13 16 55 35 318 -59 140 51 57 141 22 41 139 25 4 142 51 38
140 51 0 -39 0 0 13 16 48 36 318 -60 140 35 55 141 6 7 139 10 33 142 33 27
140 36 12 -38 0 0 13 16 42 37 318 -60 140 21 23 140 51 4 138 57 25 142 16 55
140 22 50 -37 0 0 13 16 35 38 318 -61 140 8 15 140 37 27 138 45 36 142 1 54
140 10 48 -36 0 0 13 16 28 39 317 -61 139 56 27 140 25 12 138 35 2 141 48 20
140 0 3 -35 0 0 13 16 21 39 317 -62 139 45 54 140 14 14 138 25 40 141 36 9
139 50 32 -34 0 0 13 16 13 40 317 -62 139 36 34 140 4 31 138 17 26 141 25 16
139 42 9 -33 0 0 13 16 6 41 316 -63 139 28 23 139 55 58 138 10 17 141 15 38
139 34 54 -32 0 0 13 15 59 42 316 -63 139 21 18 139 48 32 138 4 10 141 7 11
139 28 42 -31 0 0 13 15 51 43 315 -64 139 15 16 139 42 10 137 59 3 140 59 52
139 23 32 -30 0 0 13 15 43 43 315 -64 139 10 15 139 36 51 137 54 53 140 53 39
139 19 21 -29 0 0 13 15 36 44 314 -65 139 6 13 139 32 31 137 51 39 140 48 28
139 16 6 -28 0 0 13 15 28 45 314 -65 139 3 6 139 29 8 137 49 18 140 44 18
139 13 47 -27 0 0 13 15 20 46 313 -65 139 0 54 139 26 41 137 47 48 140 41 7
139 12 20 -26 0 0 13 15 12 46 312 -66 138 59 34 139 25 7 137 47 8 140 38 51
139 11 45 -25 0 0 13 15 4 47 311 -66 138 59 6 139 24 26 137 47 17 140 37 31
139 12 0 -24 0 0 13 14 56 48 311 -66 138 59 27 139 24 35 137 48 13 140 37 4
139 13 4 -23 0 0 13 14 47 48 310 -67 139 0 37 139 25 33 137 49 55 140 37 29
139 14 56 -22 0 0 13 14 39 49 309 -67 139 2 34 139 27 19 137 52 22 140 38 44
139 17 34 -21 0 0 13 14 31 50 308 -67 139 5 17 139 29 52 137 55 33 140 40 48
139 20 57 -20 0 0 13 14 22 50 307 -67 139 8 45 139 33 11 137 59 27 140 43 41
139 25 6 -19 0 0 13 14 14 51 306 -67 139 12 58 139 37 16 138 4 3 140 47 21
139 29 59 -18 0 0 13 14 5 51 305 -67 139 17 54 139 42 4 138 9 21 140 51 47
139 35 35 -17 0 0 13 13 56 52 304 -68 139 23 34 139 47 37 138 15 20 140 57 0
139 41 54 -16 0 0 13 13 47 52 303 -68 139 29 56 139 53 53 138 22 0 141 2 58
139 48 55 -15 0 0 13 13 39 53 302 -68 139 37 0 140 0 51 138 29 20 141 9 40
139 56 38 -14 0 0 13 13 30 53 300 -68 139 44 46 140 8 32 138 37 20 141 17 7
140 5 4 -13 0 0 13 13 21 54 299 -68 139 53 14 140 16 56 138 45 59 141 25 18
140 14 11 -12 0 0 13 13 12 54 298 -68 140 2 22 140 26 1 138 55 18 141 34 13
140 24 0 -11 0 0 13 13 3 54 297 -68 140 12 12 140 35 48 139 5 17 141 43 52
140 34 30 -10 0 0 13 12 53 55 295 -67 140 22 44 140 46 17 139 15 55 141 54 14
140 45 41 - 9 0 0 13 12 44 55 294 -67 140 33 56 140 57 28 139 27 13 142 5 20
140 57 35 - 8 0 0 13 12 35 55 292 -67 140 45 50 141 9 21 139 39 10 142 17 10
141 10 10 - 7 0 0 13 12 26 56 291 -67 140 58 26 141 21 56 139 51 47 142 29 45
141 23 28 - 6 0 0 13 12 16 56 289 -67 141 11 44 141 35 14 140 5 4 142 43 3
141 37 29 - 5 0 0 13 12 7 56 288 -66 141 25 44 141 49 15 140 19 2 142 57 7
141 52 12 - 4 0 0 13 11 58 56 286 -66 141 40 27 142 3 59 140 33 41 143 11 56
142 7 39 - 3 0 0 13 11 48 56 285 -66 141 55 53 142 19 28 140 49 1 143 27 31
Uncertainty in time = +/- 9 secs
Prediction of 2011 Jul 2.0
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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