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Updated: 2006 DEC 19, 07:53 UT
Event Rank : 40
(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 2006 Dec 25 UT, the 30 km diameter asteroid (1362) Griqua will occult a 10.7 mag star in the constellation Monoceros for observers along a path across SE Australia, from Mallacoota, past Albury and across southern New South Wales to around Andamooka at twighlight.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.8 mag to 14.5 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 Ron Stone, 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
156 13 8 -43 0 0 10 47 6 26 53 -13 156 45 22 155 40 28 158 29 2 153 49 30
155 6 41 -42 0 0 10 47 16 26 55 -14 155 39 15 154 33 40 157 23 50 152 41 20
153 56 40 -41 0 0 10 47 27 26 56 -14 154 29 40 153 23 11 156 15 28 151 29 3
152 42 45 -40 0 0 10 47 37 25 58 -14 153 16 18 152 8 42 155 3 42 150 12 17
151 24 35 -39 0 0 10 47 48 25 59 -14 151 58 50 150 49 47 153 48 13 148 50 30
150 1 40 -38 0 0 10 47 59 25 60 -14 150 36 47 149 25 56 152 28 39 147 23 3
148 33 23 -37 0 0 10 48 10 24 62 -14 149 9 35 147 56 29 151 4 32 145 49 4
146 58 56 -36 0 0 10 48 22 24 63 -14 147 36 29 146 20 33 149 35 18 144 7 22
145 17 14 -35 0 0 10 48 34 23 65 -13 145 56 31 144 37 0 148 0 10 142 16 20
143 26 50 -34 0 0 10 48 46 22 67 -13 144 8 20 142 44 9 146 18 9 140 13 29
141 25 35 -33 0 0 10 48 59 21 68 -12 142 10 3 140 39 38 144 27 54 137 55 1
Latitude Latitude Latitude Latitude
140 0 0 -32 21 14 10 49 7 20 69 -12 -32 0 31 -32 42 14 -30 54 6 -33 53 48
139 0 0 -31 55 46 10 49 13 19 70 -11 -31 35 18 -32 16 31 -30 29 36 -33 27 10
138 0 0 -31 31 41 10 49 19 19 71 -11 -31 11 26 -31 52 12 -30 6 26 -33 2 1
137 0 0 -31 8 59 10 49 24 18 72 -10 -30 48 57 -31 29 17 -29 44 33 -32 38 20
136 0 0 -30 47 38 10 49 29 17 72 -10 -30 27 47 -31 7 44 -29 23 58 -32 16 4
135 0 0 -30 27 37 10 49 34 17 73 -9 -30 7 56 -30 47 33 -29 4 39 -31 55 14
134 0 0 -30 8 55 10 49 38 16 74 -9 -29 49 24 -30 28 41 -28 46 36 -31 35 46
133 0 0 -29 51 31 10 49 42 15 74 -8 -29 32 9 -30 11 8 -28 29 47 -31 17 42
132 0 0 -29 35 26 10 49 47 14 75 -8 -29 16 11 -29 54 54 -28 14 13 -31 0 58
131 0 0 -29 20 37 10 49 50 14 76 -7 -29 1 29 -29 39 58 -27 59 53 -30 45 36
130 0 0 -29 7 5 10 49 54 13 76 -7 -28 48 3 -29 26 19 -27 46 47 -30 31 34
129 0 0 -28 54 48 10 49 58 12 77 -6 -28 35 53 -29 13 58 -27 34 54 -30 18 51
128 0 0 -28 43 48 10 50 1 11 77 -5 -28 24 57 -29 2 52 -27 24 13 -30 7 27
127 0 0 -28 34 3 10 50 4 10 78 -5 -28 15 16 -28 53 2 -27 14 45 -29 57 22
126 0 0 -28 25 33 10 50 7 10 78 -4 -28 6 50 -28 44 29 -27 6 30 -29 48 34
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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