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Updated: 2012 JUL 07, 23:31 UT
Event Rank : 38
(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 Aug 20 UT, the 56 km diameter asteroid (1005) Arago will occult a 11.6 mag star in the constellation Scorpius for observers along a path across North Island New Zealand near Napier and Auckland.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.9 mag to 15.4 mag (the magnitude of the asteroid) for at most 5.8 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
173 28 27 -27 0 0 9 34 29 67 213 -46 173 46 29 173 10 27 174 49 7 172 8 27
173 42 50 -28 0 0 9 34 18 68 214 -46 174 1 2 173 24 39 175 4 20 172 22 1
173 57 47 -29 0 0 9 34 7 69 216 -46 174 16 12 173 39 25 175 20 10 172 36 7
174 13 22 -30 0 0 9 33 56 69 218 -46 174 31 58 173 54 47 175 36 40 172 50 47
174 29 34 -31 0 0 9 33 45 70 220 -46 174 48 24 174 10 47 175 53 51 173 6 3
174 46 27 -32 0 0 9 33 33 71 222 -46 175 5 31 174 27 26 176 11 46 173 21 56
175 4 2 -33 0 0 9 33 22 71 224 -46 175 23 20 174 44 47 176 30 26 173 38 27
175 22 21 -34 0 0 9 33 11 72 227 -46 175 41 54 175 2 51 176 49 54 173 55 39
175 41 26 -35 0 0 9 32 59 72 230 -46 176 1 16 175 21 40 177 10 12 174 13 33
176 1 21 -36 0 0 9 32 48 73 232 -46 176 21 27 175 41 17 177 31 23 174 32 13
176 22 6 -37 0 0 9 32 36 73 235 -46 176 42 30 176 1 45 177 53 30 174 51 39
176 43 46 -38 0 0 9 32 24 73 238 -45 177 4 29 176 23 6 178 16 36 175 11 56
177 6 23 -39 0 0 9 32 13 74 242 -45 177 27 27 176 45 23 178 40 44 175 33 5
177 30 2 -40 0 0 9 32 1 74 245 -45 177 51 26 177 8 40 179 5 58 175 55 10
177 54 45 -41 0 0 9 31 49 74 248 -45 178 16 32 177 33 1 179 32 24 176 18 15
178 20 36 -42 0 0 9 31 37 74 252 -45 178 42 48 177 58 29 -179 59 56 176 42 22
178 47 42 -43 0 0 9 31 26 74 255 -44 179 10 18 178 25 9 -179 30 56 177 7 37
179 16 5 -44 0 0 9 31 14 74 259 -44 179 39 9 178 53 6 -179 0 30 177 34 3
179 45 53 -45 0 0 9 31 2 74 262 -44 -179 50 35 179 22 25 -178 28 33 178 1 46
-179 42 49 -46 0 0 9 30 50 74 265 -44 -179 18 47 179 53 12 -177 54 57 178 30 51
Uncertainty in time = +/- 10 secs
Prediction of 2012 Jul 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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