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Updated: 2011 Sep 23, 22:27 UT
Event Rank : 81
(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 Oct 20 UT, the 104 km diameter asteroid (788) Hohensteina will occult a 12.1 mag star in the constellation Orion for observers along a path running down the eastern coast of Australia, beginning near Rockhampton and running all the way to the southern coast of Tasmania.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 14.2 mag (the magnitude of the asteroid) for at most 13.1 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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 0144-02861-1 by 788 Hohensteina on 2011 Oct 20
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
145 6 1 -45 0 0 15 5 50 19 58 -33 143 48 49 146 20 37 142 2 22 147 55 37
145 55 32 -44 0 0 15 5 41 20 58 -34 144 41 18 147 7 26 142 59 15 148 39 11
146 40 31 -43 0 0 15 5 32 21 58 -35 145 28 54 147 50 2 143 50 42 149 18 53
147 21 26 -42 0 0 15 5 22 22 58 -35 146 12 7 148 28 48 144 37 19 149 55 3
147 58 37 -41 0 0 15 5 12 23 57 -36 146 51 23 149 4 4 145 19 35 150 27 58
148 32 25 -40 0 0 15 5 2 24 57 -37 147 27 3 149 36 8 145 57 57 150 57 55
149 3 7 -39 0 0 15 4 52 25 57 -38 147 59 26 150 5 15 146 32 44 151 25 6
149 30 55 -38 0 0 15 4 42 26 57 -38 148 28 45 150 31 38 147 4 14 151 49 44
149 56 4 -37 0 0 15 4 31 26 58 -39 148 55 16 150 55 28 147 32 43 152 11 58
150 18 42 -36 0 0 15 4 20 27 58 -40 149 19 10 151 16 56 147 58 24 152 31 57
150 39 0 -35 0 0 15 4 9 28 58 -41 149 40 37 151 36 9 148 21 27 152 49 49
150 57 6 -34 0 0 15 3 57 29 58 -42 149 59 45 151 53 16 148 42 4 153 5 42
151 13 7 -33 0 0 15 3 46 29 58 -42 150 16 44 152 8 23 149 0 22 153 19 42
151 27 10 -32 0 0 15 3 34 30 59 -43 150 31 38 152 21 36 149 16 30 153 31 54
151 39 20 -31 0 0 15 3 22 31 59 -44 150 44 36 152 33 1 149 30 33 153 42 22
151 49 43 -30 0 0 15 3 10 31 60 -45 150 55 41 152 42 42 149 42 39 153 51 11
151 58 22 -29 0 0 15 2 58 32 60 -46 151 4 59 152 50 44 149 52 51 153 58 26
152 5 21 -28 0 0 15 2 45 32 60 -46 151 12 33 152 57 9 150 1 14 154 4 9
152 10 44 -27 0 0 15 2 33 33 61 -47 151 18 28 153 2 2 150 7 53 154 8 23
152 14 34 -26 0 0 15 2 20 33 62 -48 151 22 46 153 5 24 150 12 51 154 11 10
152 16 52 -25 0 0 15 2 7 34 62 -49 151 25 30 153 7 19 150 16 10 154 12 34
152 17 43 -24 0 0 15 1 54 34 63 -50 151 26 43 153 7 47 150 17 52 154 12 35
152 17 6 -23 0 0 15 1 41 35 63 -51 151 26 25 153 6 52 150 18 1 154 11 16
152 15 4 -22 0 0 15 1 27 35 64 -52 151 24 39 153 4 34 150 16 38 154 8 37
152 11 37 -21 0 0 15 1 14 35 65 -52 151 21 26 153 0 54 150 13 43 154 4 40
152 6 47 -20 0 0 15 1 0 36 66 -53 151 16 47 152 55 53 150 9 19 153 59 25
152 0 34 -19 0 0 15 0 46 36 66 -54 151 10 43 152 49 32 150 3 25 153 52 53
151 52 59 -18 0 0 15 0 32 36 67 -55 151 3 12 152 41 51 149 56 1 153 45 4
Uncertainty in time = +/- 11 secs
Prediction of 2011 Sep 24.0
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[Planetary Occultations]
[Using the Predictions]
[Observing Details]
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