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Updated: 2012 Oct 07, 18:54 UT
Event Rank : 33
(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 Oct 16 UT, the 26 km diameter asteroid (1222) Tina will occult a 8.2 mag star in the constellation Triangulum for observers along a path across south-east Queensland and central New South Wales, passing near Toowoomba and Brisbane.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.8 mag to 14.0 mag (the magnitude of the asteroid) for at most 2.1 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: .
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 2308-00989-1 by 1222 Tina on 2012 Oct 16
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
141 19 34 -37 0 0 11 4 3 4 46 -25 141 6 42 141 32 25 140 13 43 142 24 51
142 36 54 -36 0 0 11 4 2 5 45 -26 142 24 19 142 49 27 141 32 33 143 40 45
143 51 52 -35 0 0 11 4 1 7 44 -28 143 39 33 144 4 10 142 48 53 144 54 23
145 4 40 -34 0 0 11 3 59 8 44 -29 144 52 36 145 16 43 144 2 58 146 5 58
146 15 30 -33 0 0 11 3 57 9 43 -31 146 3 40 146 27 20 145 14 58 147 15 41
147 24 32 -32 0 0 11 3 55 11 42 -32 147 12 54 147 36 9 146 25 5 148 23 39
148 31 54 -31 0 0 11 3 52 12 42 -33 148 20 28 148 43 20 147 33 27 149 30 4
149 37 45 -30 0 0 11 3 50 14 41 -35 149 26 30 149 49 0 148 40 13 150 35 1
150 42 12 -29 0 0 11 3 47 15 41 -36 150 31 7 150 53 17 149 45 32 151 38 38
151 45 23 -28 0 0 11 3 43 16 40 -37 151 34 26 151 56 18 150 49 30 152 41 2
152 47 22 -27 0 0 11 3 40 18 40 -39 152 36 35 152 58 9 151 52 14 153 42 18
153 48 17 -26 0 0 11 3 36 19 39 -40 153 37 37 153 58 56 152 53 50 154 42 33
154 48 12 -25 0 0 11 3 32 20 39 -41 154 37 40 154 58 44 153 54 24 155 41 51
155 47 13 -24 0 0 11 3 28 22 38 -43 155 36 48 155 57 39 154 54 1 156 40 18
Uncertainty in time = +/- 5 secs
Prediction of 2012 Oct 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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