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Updated: 2013 SEP 08, 20:41 UT
Event Rank : 63
(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 Oct 28 UT, the 36 km diameter asteroid (1233) Kobresia will occult a 11.2 mag star in the constellation Aries for observers along a narrow path across south-eastern Australia from Balina across NSW to near Mildura and across south-east South Australia to near Goolwa.
In the case of an occultation, the combined light of the asteroid and the star will drop by 4.0 mag to 15.2 mag (the magnitude of the asteroid) for at most 3.4 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
132 28 31 -40 0 0 14 12 17 18 28 -36 131 57 4 133 0 9 130 57 12 134 1 28
134 4 11 -39 0 0 14 12 9 19 26 -37 133 32 35 134 35 59 132 32 27 135 37 40
135 41 45 -38 0 0 14 12 0 21 25 -38 135 9 56 136 13 48 134 9 25 137 15 58
137 21 29 -37 0 0 14 11 50 22 24 -40 136 49 22 137 53 50 135 48 20 138 56 39
139 3 39 -36 0 0 14 11 40 24 23 -41 138 31 10 139 36 23 137 29 29 140 40 0
140 48 35 -35 0 0 14 11 28 25 21 -42 140 15 39 141 21 48 139 13 10 142 26 23
142 36 39 -34 0 0 14 11 16 26 20 -43 142 3 10 143 10 27 140 59 41 144 16 14
144 28 18 -33 0 0 14 11 3 28 18 -44 143 54 8 145 2 47 142 49 28 146 10 1
146 24 2 -32 0 0 14 10 48 29 16 -45 145 49 4 146 59 22 144 42 57 148 8 21
148 24 28 -31 0 0 14 10 32 31 15 -46 147 48 32 149 0 50 146 40 41 150 11 55
Latitude Latitude Latitude Latitude
149 0 0 -30 42 47 14 10 27 31 14 -46 -30 25 18 -31 0 24 -29 52 3 -31 34 35
150 0 0 -30 14 13 14 10 19 32 13 -46 -29 56 51 -30 31 43 -29 23 49 -31 5 40
151 0 0 -29 46 18 14 10 11 32 12 -46 -29 29 3 -30 3 41 -28 56 13 -30 37 24
152 0 0 -29 19 2 14 10 2 33 11 -47 -29 1 53 -29 36 18 -28 29 16 -30 9 48
153 0 0 -28 52 25 14 9 54 34 10 -47 -28 35 23 -29 9 35 -28 2 58 -29 42 51
154 0 0 -28 26 28 14 9 45 34 9 -47 -28 9 32 -28 43 31 -27 37 18 -29 16 35
155 0 0 -28 1 11 14 9 36 35 8 -47 -27 44 20 -28 18 8 -27 12 18 -28 50 59
156 0 0 -27 36 33 14 9 27 35 7 -47 -27 19 49 -27 53 24 -26 47 58 -28 26 4
157 0 0 -27 12 36 14 9 19 36 6 -48 -26 55 57 -27 29 21 -26 24 17 -28 1 50
Uncertainty in time = +/- 5 secs
Prediction of 2013 Sep 8.0
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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