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Updated: 2014 APR 10, 02:51 UT
Event Rank : 46
(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 2015 Mar 26 UT, the 35 km diameter asteroid (916) America will occult a 10.4 mag star in the constellation Cancer for observers along a path across Australia, from west of Adelaide across South Australia and western Queensland, passing west of Mt Isa.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.6 mag to 16.0 mag (the magnitude of the asteroid) for at most 9.6 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.
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
137 11 15 -38 0 0 12 18 46 31 343 -39 136 58 8 137 24 23 136 21 29 138 1 16
137 10 10 -37 0 0 12 18 29 32 343 -40 136 57 13 137 23 7 136 21 4 137 59 31
137 9 48 -36 0 0 12 18 12 33 343 -40 136 57 2 137 22 36 136 21 20 137 58 31
137 10 9 -35 0 0 12 17 54 34 343 -41 136 57 32 137 22 47 136 22 16 137 58 16
137 11 10 -34 0 0 12 17 35 35 343 -41 136 58 42 137 23 40 136 23 51 137 58 43
137 12 51 -33 0 0 12 17 16 36 343 -42 137 0 31 137 25 11 136 26 4 137 59 51
137 15 9 -32 0 0 12 16 57 37 342 -42 137 2 57 137 27 21 136 28 52 138 1 38
137 18 3 -31 0 0 12 16 37 38 342 -43 137 5 59 137 30 8 136 32 15 138 4 3
137 21 33 -30 0 0 12 16 17 39 342 -43 137 9 36 137 33 31 136 36 13 138 7 5
137 25 37 -29 0 0 12 15 56 40 342 -43 137 13 47 137 37 28 136 40 43 138 10 44
137 30 15 -28 0 0 12 15 35 41 341 -44 137 18 31 137 41 59 136 45 45 138 14 56
137 35 25 -27 0 0 12 15 13 42 341 -44 137 23 47 137 47 3 136 51 18 138 19 43
137 41 6 -26 0 0 12 14 51 42 341 -45 137 29 34 137 52 39 136 57 21 138 25 3
137 47 19 -25 0 0 12 14 29 43 341 -45 137 35 52 137 58 46 137 3 54 138 30 55
137 54 2 -24 0 0 12 14 6 44 340 -46 137 42 40 138 5 24 137 10 56 138 37 18
138 1 14 -23 0 0 12 13 43 45 340 -46 137 49 57 138 12 31 137 18 27 138 44 12
138 8 55 -22 0 0 12 13 20 46 340 -46 137 57 43 138 20 8 137 26 26 138 51 36
138 17 5 -21 0 0 12 12 56 47 339 -47 138 5 58 138 28 14 137 34 52 138 59 30
138 25 43 -20 0 0 12 12 32 48 339 -47 138 14 39 138 36 48 137 43 44 139 7 52
138 34 49 -19 0 0 12 12 7 49 338 -48 138 23 49 138 45 50 137 53 4 139 16 44
138 44 21 -18 0 0 12 11 42 50 338 -48 138 33 25 138 55 19 138 2 50 139 26 3
138 54 21 -17 0 0 12 11 17 51 337 -48 138 43 27 139 5 15 138 13 1 139 35 51
139 4 47 -16 0 0 12 10 51 52 337 -49 138 53 56 139 15 38 138 23 38 139 46 6
139 15 39 -15 0 0 12 10 25 53 336 -49 139 4 51 139 26 28 138 34 41 139 56 48
139 26 57 -14 0 0 12 9 59 53 335 -49 139 16 12 139 37 44 138 46 8 140 7 57
139 38 42 -13 0 0 12 9 33 54 335 -50 139 27 58 139 49 25 138 58 1 140 19 32
139 50 51 -12 0 0 12 9 6 55 334 -50 139 40 10 140 1 33 139 10 18 140 31 35
140 3 27 -11 0 0 12 8 39 56 333 -50 139 52 47 140 14 7 139 23 0 140 44 3
140 16 27 -10 0 0 12 8 11 57 332 -50 140 5 49 140 27 6 139 36 7 140 56 58
140 29 54 - 9 0 0 12 7 43 58 331 -51 140 19 17 140 40 31 139 49 38 141 10 19
140 43 45 - 8 0 0 12 7 15 58 330 -51 140 33 10 140 54 21 140 3 34 141 24 7
140 58 2 - 7 0 0 12 6 47 59 329 -51 140 47 27 141 8 38 140 17 54 141 38 20
141 12 45 - 6 0 0 12 6 19 60 328 -51 141 2 11 141 23 19 140 32 39 141 53 0
141 27 52 - 5 0 0 12 5 50 61 327 -51 141 17 19 141 38 27 140 47 49 142 8 7
141 43 26 - 4 0 0 12 5 21 62 326 -52 141 32 53 141 54 0 141 3 23 142 23 39
141 59 25 - 3 0 0 12 4 52 62 325 -52 141 48 52 142 9 59 141 19 23 142 39 39
Uncertainty in time = +/- 14 secs
Prediction of 2015 Feb 12.0
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