|
|
Updated: 2013 JUL 05, 16:02 UT
Event Rank : 65
(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 2013 Aug 22 UT, the 152 km diameter asteroid (361) Bononia will occult a 12.1 mag star in the constellation Scorpius for observers along a path across Pacific Ocean.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.4 mag to 15.5 mag (the magnitude of the asteroid) for at most 28.3 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, 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
178 15 33 -28 0 0 8 24 59 77 220 -35 179 5 36 177 25 45 -179 20 39 175 53 41
178 39 6 -29 0 0 8 24 38 78 224 -35 179 29 42 177 48 45 -178 55 29 176 15 41
179 3 18 -30 0 0 8 24 17 78 228 -35 179 54 29 178 12 22 -178 29 35 176 38 15
179 28 9 -31 0 0 8 23 55 78 232 -36 -179 40 3 178 36 37 -178 2 56 177 1 24
179 53 43 -32 0 0 8 23 34 79 237 -36 -179 13 50 179 1 32 -177 35 28 177 25 9
-179 39 59 -33 0 0 8 23 12 79 242 -36 -178 46 50 179 27 9 -177 7 9 177 49 33
-179 12 54 -34 0 0 8 22 51 79 247 -36 -178 19 1 179 53 32 -176 37 57 178 14 37
-178 44 59 -35 0 0 8 22 29 79 253 -36 -177 50 21 -179 39 19 -176 7 48 178 40 25
-178 16 12 -36 0 0 8 22 7 79 258 -36 -177 20 45 -179 11 20 -175 36 39 179 6 57
-177 46 30 -37 0 0 8 21 46 79 263 -36 -176 50 11 -178 42 28 -175 4 26 179 34 18
-177 15 48 -38 0 0 8 21 24 79 269 -36 -176 18 35 -178 12 40 -174 31 6 -179 57 31
Latitude Latitude Latitude Latitude
-177 0 0 -38 30 9 8 21 13 78 271 -36 -36 40 56 -40 18 30 -33 14 53 -43 38 19
-176 0 0 -40 20 3 8 20 33 78 279 -36 -38 34 21 -42 5 1 -35 15 13 -45 18 45
-175 0 0 -42 3 13 8 19 55 77 286 -37 -40 20 49 -43 44 59 -37 8 6 -46 52 58
-174 0 0 -43 40 7 8 19 20 76 291 -37 -42 0 48 -45 18 52 -38 54 6 -48 21 23
-173 0 0 -45 11 11 8 18 46 74 294 -37 -43 34 47 -46 47 5 -40 33 44 -49 44 26
-172 0 0 -46 36 50 8 18 15 73 297 -37 -45 3 11 -48 10 2 -42 7 27 -51 2 27
-171 0 0 -47 57 27 8 17 45 72 300 -37 -46 26 24 -49 28 5 -43 35 40 -52 15 50
-170 0 0 -49 13 23 8 17 17 71 301 -36 -47 44 48 -50 41 34 -44 58 46 -53 24 52
-169 0 0 -50 24 56 8 16 51 70 303 -36 -48 58 42 -51 50 49 -46 17 8 -54 29 53
Uncertainty in time = +/- 27 secs
Prediction of 2013 Jul 4.0
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]