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Updated: 2012 JAN 14, 17:22 UT
Event Rank : 29
(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 Feb 07 UT, the 20 km diameter asteroid (2479) Sodankyla will occult a 10.3 mag star in the constellation Gemini for observers along a quite narrow north-to-south path across New Zealand passing near Nelson and Blenheim.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.4 mag to 15.7 mag (the magnitude of the asteroid) for at most 12.8 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
175 6 0 -46 0 0 10 42 24 17 342 -24 174 57 49 175 14 11 174 20 28 175 51 44
174 44 39 -45 0 0 10 42 2 18 342 -24 174 36 38 174 52 40 174 0 0 175 29 29
174 24 37 -44 0 0 10 41 39 19 343 -25 174 16 46 174 32 30 173 40 49 175 8 37
174 5 51 -43 0 0 10 41 14 20 343 -26 173 58 7 174 13 34 173 22 50 174 49 2
173 48 15 -42 0 0 10 40 48 21 343 -27 173 40 40 173 55 51 173 5 59 174 30 41
173 31 47 -41 0 0 10 40 21 22 343 -27 173 24 19 173 39 14 172 50 13 174 13 29
173 16 22 -40 0 0 10 39 53 23 344 -28 173 9 2 173 23 43 172 35 29 173 57 24
173 1 58 -39 0 0 10 39 23 24 344 -29 172 54 45 173 9 12 172 21 43 173 42 21
172 48 32 -38 0 0 10 38 53 25 344 -29 172 41 25 172 55 39 172 8 53 173 28 19
172 36 1 -37 0 0 10 38 21 26 344 -30 172 29 1 172 43 2 171 56 57 173 15 13
172 24 23 -36 0 0 10 37 48 27 344 -31 172 17 28 172 31 18 171 45 51 173 3 2
172 13 35 -35 0 0 10 37 14 28 345 -31 172 6 46 172 20 25 171 35 34 172 51 43
172 3 36 -34 0 0 10 36 39 29 345 -32 171 56 52 172 10 20 171 26 4 172 41 14
171 54 22 -33 0 0 10 36 3 30 345 -33 171 47 43 172 1 1 171 17 18 172 31 32
171 45 53 -32 0 0 10 35 25 31 345 -33 171 39 19 171 52 27 171 9 16 172 22 36
171 38 6 -31 0 0 10 34 47 32 345 -34 171 31 37 171 44 36 171 1 54 172 14 24
171 31 0 -30 0 0 10 34 7 33 345 -34 171 24 35 171 37 26 170 55 12 172 6 54
171 24 33 -29 0 0 10 33 26 34 345 -35 171 18 12 171 30 55 170 49 8 172 0 4
171 18 44 -28 0 0 10 32 45 35 346 -36 171 12 26 171 25 1 170 43 40 171 53 53
171 13 31 -27 0 0 10 32 2 37 346 -36 171 7 17 171 19 45 170 38 47 171 48 19
Uncertainty in time = +/- 29 secs
Prediction of 2012 Jan 15.0
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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