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Updated: 2012 Jul 07, 22:33 UT
Event Rank : 26
(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 2012 Jul 30 UT, the 12 km diameter asteroid (422) Berolina will occult a 9.5 mag star in the constellation Scorpius for observers along a path across western Queensland and eastern South Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 4.2 mag to 13.7 mag (the magnitude of the asteroid) for at most 6.2 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: 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.
Occultation of TYC 7360-01551-1 by 422 Berolina on 2012 Jul 30
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
142 2 28 -10 0 0 12 24 7 60 221 -56 142 5 56 141 59 0 142 23 56 141 41 2
141 56 16 -11 0 0 12 23 15 61 222 -56 141 59 44 141 52 47 142 17 46 141 34 48
141 50 19 -12 0 0 12 22 23 62 222 -56 141 53 47 141 46 50 142 11 51 141 28 49
141 44 35 -13 0 0 12 21 29 63 223 -56 141 48 5 141 41 6 142 6 10 141 23 2
141 39 5 -14 0 0 12 20 36 64 224 -56 141 42 35 141 35 35 142 0 44 141 17 29
141 33 47 -15 0 0 12 19 42 65 225 -56 141 37 17 141 30 16 141 55 29 141 12 7
141 28 40 -16 0 0 12 18 48 66 227 -56 141 32 11 141 25 9 141 50 27 141 6 55
141 23 43 -17 0 0 12 17 53 67 228 -56 141 27 15 141 20 11 141 45 35 141 1 54
141 18 56 -18 0 0 12 16 58 68 229 -56 141 22 29 141 15 23 141 40 53 140 57 1
141 14 17 -19 0 0 12 16 3 69 231 -56 141 17 51 141 10 43 141 36 19 140 52 16
141 9 45 -20 0 0 12 15 8 69 233 -55 141 13 20 141 6 10 141 31 54 140 47 38
141 5 20 -21 0 0 12 14 12 70 234 -55 141 8 56 141 1 44 141 27 36 140 43 6
141 1 1 -22 0 0 12 13 16 71 236 -55 141 4 38 140 57 24 141 23 24 140 38 39
140 56 46 -23 0 0 12 12 19 72 239 -55 141 0 25 140 53 7 141 19 18 140 34 16
140 52 35 -24 0 0 12 11 23 73 241 -54 140 56 15 140 48 55 141 15 15 140 29 57
140 48 26 -25 0 0 12 10 26 73 244 -54 140 52 8 140 44 45 141 11 16 140 25 39
140 44 20 -26 0 0 12 9 29 74 246 -54 140 48 3 140 40 37 141 7 19 140 21 22
140 40 14 -27 0 0 12 8 32 75 249 -53 140 43 59 140 36 29 141 3 24 140 17 6
140 36 7 -28 0 0 12 7 35 75 253 -53 140 39 54 140 32 21 140 59 29 140 12 48
140 32 0 -29 0 0 12 6 38 76 256 -53 140 35 48 140 28 11 140 55 33 140 8 28
140 27 49 -30 0 0 12 5 40 76 260 -52 140 31 40 140 23 59 140 51 35 140 4 5
140 23 35 -31 0 0 12 4 43 76 264 -52 140 27 28 140 19 43 140 47 35 139 59 38
140 19 17 -32 0 0 12 3 45 77 269 -51 140 23 12 140 15 22 140 43 30 139 55 5
140 14 52 -33 0 0 12 2 47 77 273 -51 140 18 50 140 10 55 140 39 21 139 50 25
140 10 20 -34 0 0 12 1 50 77 278 -50 140 14 20 140 6 20 140 35 5 139 45 37
140 5 40 -35 0 0 12 0 52 77 283 -50 140 9 43 140 1 37 140 30 41 139 40 40
140 0 50 -36 0 0 11 59 54 77 287 -49 140 4 55 139 56 44 140 26 8 139 35 32
139 55 48 -37 0 0 11 58 56 77 292 -49 139 59 57 139 51 39 140 21 26 139 30 12
139 50 34 -38 0 0 11 57 59 77 297 -48 139 54 46 139 46 22 140 16 31 139 24 38
139 45 5 -39 0 0 11 57 1 77 301 -48 139 49 21 139 40 50 140 11 24 139 18 48
139 39 21 -40 0 0 11 56 4 76 306 -47 139 43 40 139 35 2 140 6 1 139 12 42
139 33 19 -41 0 0 11 55 6 76 310 -47 139 37 41 139 28 56 140 0 23 139 6 16
139 26 57 -42 0 0 11 54 9 75 314 -46 139 31 24 139 22 31 139 54 26 138 59 30
139 20 14 -43 0 0 11 53 11 75 317 -46 139 24 45 139 15 44 139 48 9 138 52 21
139 13 8 -44 0 0 11 52 14 74 321 -45 139 17 43 139 8 33 139 41 30 138 44 47
139 5 36 -45 0 0 11 51 17 74 324 -44 139 10 16 139 0 56 139 34 27 138 36 46
Uncertainty in time = +/- 15 secs
Prediction of 2012 Jul 8.0
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