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Updated: 2009 AUG 01, 15:45 UT
Event Rank : 64
(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 2009 Sep 04 UT, the 123 km diameter asteroid (1867) Deiphobus will occult a 10.7 mag star in the constellation Scorpius for observers along a path off the east coast of New Zealand.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.5 mag to 16.2 mag (the magnitude of the asteroid) for at most 7.7 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 Limit1 Path Limit2 Error Limit1 Error Limit2
E. Longitude Latitude U.T. Alt Az Alt
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
177 57 28 -56 0 20 10 55 4 34 262 -39 176 13 37 -56 2 54 179 43 39 -55 56 4 173 0 36 -56 3 29 -176 45 40 -55 42 37
178 7 31 -55 8 41 10 55 10 34 261 -40 176 25 31 -55 11 28 179 51 49 -55 4 13 173 15 59 -55 12 29 -176 41 6 -54 50 26
178 19 5 -54 16 50 10 55 16 33 260 -41 176 38 48 -54 19 50 -179 58 20 -54 12 9 173 32 28 -54 21 20 -176 34 34 -53 57 57
178 32 8 -53 24 45 10 55 22 33 260 -42 176 53 25 -53 28 1 -179 46 52 -53 19 48 173 50 3 -53 30 1 -176 26 7 -53 5 7
178 46 37 -52 32 24 10 55 28 33 259 -42 177 9 21 -52 35 57 -179 33 49 -52 27 10 174 8 42 -52 38 31 -176 15 49 -52 11 55
179 2 31 -51 39 45 10 55 34 32 258 -43 177 26 33 -51 43 38 -179 19 13 -51 34 12 174 28 24 -51 46 48 -176 3 41 -51 18 19
179 19 49 -50 46 48 10 55 40 32 257 -44 177 45 2 -50 51 1 -179 3 6 -50 40 53 174 49 10 -50 54 50 -175 49 46 -50 24 17
179 38 30 -49 53 28 10 55 46 32 257 -45 178 4 47 -49 58 4 -178 45 28 -49 47 10 175 10 58 -50 2 36 -175 34 3 -49 29 45
179 58 34 -48 59 45 10 55 52 31 256 -46 178 25 48 -49 4 46 -178 26 19 -48 53 1 175 33 50 -49 10 3 -175 16 33 -48 34 41
-179 39 57 -48 5 36 10 55 57 31 255 -47 178 48 7 -48 11 4 -178 5 38 -47 58 23 175 57 47 -48 17 10 -174 57 14 -47 39 1
-179 17 2 -47 10 57 10 56 3 30 254 -48 179 11 44 -47 16 54 -177 43 23 -47 3 12 176 22 50 -47 23 53 -174 36 5 -46 42 43
-178 52 40 -46 15 45 10 56 9 30 254 -49 179 36 41 -46 22 15 -177 19 32 -46 7 26 176 49 0 -46 30 11 -174 13 1 -45 45 41
-178 26 46 -45 19 58 10 56 15 29 253 -50 -179 56 59 -45 27 3 -176 54 2 -45 11 0 177 16 21 -45 36 0 -173 48 0 -44 47 51
-177 59 19 -44 23 30 10 56 21 28 252 -51 -179 29 12 -44 31 14 -176 26 49 -44 13 51 177 44 54 -44 41 18 -173 20 55 -43 49 7
-177 30 12 -43 26 18 10 56 27 28 251 -52 -178 59 54 -43 34 45 -175 57 47 -43 15 52 178 14 44 -43 46 2 -172 51 39 -42 49 23
-176 59 21 -42 28 17 10 56 33 27 251 -53 -178 29 1 -42 37 30 -175 26 49 -42 16 59 178 45 54 -42 50 6 -172 20 2 -41 48 30
-176 26 37 -41 29 19 10 56 39 26 250 -54 -177 56 27 -41 39 25 -174 53 49 -41 17 3 179 18 30 -41 53 28 -171 45 54 -40 46 20
-175 51 53 -40 29 20 10 56 45 26 249 -55 -177 22 2 -40 40 23 -174 18 34 -40 15 58 179 52 38 -40 56 2 -171 8 59 -39 42 41
-175 14 58 -39 28 9 10 56 51 25 248 -56 -176 45 40 -39 40 17 -173 40 54 -39 13 34 -179 31 36 -39 57 42 -170 28 58 -38 37 19
-174 35 38 -38 25 38 10 56 56 24 247 -57 -176 7 8 -38 39 0 -173 0 30 -38 9 39 -178 54 2 -38 58 23 -169 45 26 -37 29 56
-173 53 38 -37 21 35 10 57 2 23 247 -59 -175 26 12 -37 36 20 -172 17 4 -37 3 58 -178 14 31 -37 57 56 -168 57 51 -36 20 11
Uncertainty in time = +/- 12 secs
Prediction of 2009 Jul 25.0
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