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Updated: 2011 Oct 13, 17:03 UT
Event Rank : 88
(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 2011 Oct 28 UT, the 60 km diameter asteroid (248) Lameia will occult a 11.1 mag star in the constellation Gemini for observers along a path across central South Australia, northern New South Wales and the north island of New Zealand, passing over Coffs Harbour and Palmeston North.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.8 mag to 14.9 mag (the magnitude of the asteroid) for at most 13.8 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.
Occultation of TYC 1342-01819-1 by 248 Lameia on 2011 Oct 28
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
178 26 21 -42 0 0 15 6 50 24 20 -19 177 21 28 179 29 19 176 6 17 -179 22 11
177 15 34 -41 0 0 15 6 16 24 22 -20 176 9 24 178 19 39 174 52 30 179 29 13
176 0 41 -40 0 0 15 5 41 25 23 -22 174 52 52 177 6 12 173 33 48 178 17 8
174 41 9 -39 0 0 15 5 3 25 25 -23 173 31 14 175 48 27 172 9 25 177 1 8
173 16 13 -38 0 0 15 4 23 26 27 -25 172 3 39 174 25 49 170 38 16 175 40 40
171 44 57 -37 0 0 15 3 41 26 28 -26 170 28 58 172 57 27 168 58 58 174 15 4
170 6 3 -36 0 0 15 2 55 26 30 -28 168 45 34 171 22 17 167 9 22 172 43 26
168 17 37 -35 0 0 15 2 6 26 32 -30 166 51 5 169 38 48 165 6 15 171 4 33
166 16 51 -34 0 0 15 1 13 26 35 -32 164 41 44 167 44 50 162 44 3 169 16 41
165 0 0 -33 25 27 15 0 39 26 36 -33 -34 7 59 -32 44 4 -34 57 9 -31 59 1
164 0 0 -33 0 22 15 0 14 25 37 -34 -33 42 21 -32 19 31 -34 30 50 -31 34 59
163 0 0 -32 36 56 14 59 49 25 38 -35 -33 18 24 -31 56 33 -34 6 15 -31 12 31
162 0 0 -32 15 6 14 59 24 25 39 -36 -32 56 5 -31 35 10 -33 43 22 -30 51 36
161 0 0 -31 54 52 14 59 0 25 40 -37 -32 35 25 -31 15 20 -33 22 9 -30 32 11
160 0 0 -31 36 11 14 58 36 24 41 -38 -32 16 20 -30 57 2 -33 2 35 -30 14 16
159 0 0 -31 19 3 14 58 13 24 42 -38 -31 58 49 -30 40 14 -32 44 37 -29 57 50
158 0 0 -31 3 25 14 57 51 23 43 -39 -31 42 52 -30 24 56 -32 28 15 -29 42 51
157 0 0 -30 49 18 14 57 29 23 44 -40 -31 28 25 -30 11 5 -32 13 26 -29 29 19
156 0 0 -30 36 38 14 57 7 22 45 -40 -31 15 29 -29 58 42 -32 0 10 -29 17 12
155 0 0 -30 25 27 14 56 46 22 46 -41 -31 4 2 -29 47 44 -31 48 25 -29 6 29
154 0 0 -30 15 41 14 56 26 21 47 -42 -30 54 3 -29 38 11 -31 38 9 -28 57 9
153 0 0 -30 7 21 14 56 6 21 48 -42 -30 45 31 -29 30 2 -31 29 23 -28 49 12
152 0 0 -30 0 25 14 55 47 20 48 -43 -30 38 25 -29 23 16 -31 22 4 -28 42 37
151 0 0 -29 54 53 14 55 29 19 49 -43 -30 32 43 -29 17 53 -31 16 11 -28 37 22
150 0 0 -29 50 43 14 55 11 19 50 -44 -30 28 26 -29 13 50 -31 11 44 -28 33 27
149 0 0 -29 47 55 14 54 54 18 51 -44 -30 25 31 -29 11 8 -31 8 42 -28 30 51
148 0 0 -29 46 28 14 54 38 17 51 -45 -30 23 59 -29 9 46 -31 7 4 -28 29 34
147 0 0 -29 46 22 14 54 22 17 52 -45 -30 23 49 -29 9 43 -31 6 49 -28 29 35
146 0 0 -29 47 35 14 54 7 16 53 -45 -30 25 0 -29 10 59 -31 7 57 -28 30 53
145 0 0 -29 50 7 14 53 53 15 53 -45 -30 27 30 -29 13 32 -31 10 26 -28 33 28
144 0 0 -29 53 57 14 53 39 14 54 -46 -30 31 21 -29 17 22 -31 14 17 -28 37 18
143 0 0 -29 59 6 14 53 27 13 55 -46 -30 36 31 -29 22 30 -31 19 28 -28 42 25
142 0 0 -30 5 32 14 53 14 13 55 -46 -30 42 59 -29 28 53 -31 25 59 -28 48 46
141 0 0 -30 13 15 14 53 3 12 56 -46 -30 50 46 -29 36 33 -31 33 51 -28 56 22
140 0 0 -30 22 14 14 52 53 11 57 -46 -30 59 50 -29 45 28 -31 43 1 -29 5 12
139 0 0 -30 32 30 14 52 43 10 57 -46 -31 10 12 -29 55 38 -31 53 31 -29 15 16
138 0 0 -30 44 1 14 52 34 9 58 -46 -31 21 51 -30 7 2 -32 5 19 -29 26 33
137 0 0 -30 56 48 14 52 26 8 58 -46 -31 34 47 -30 19 41 -32 18 26 -29 39 3
136 0 0 -31 10 51 14 52 18 8 59 -46 -31 49 0 -30 33 34 -32 32 50 -29 52 46
135 0 0 -31 26 9 14 52 12 7 59 -45 -32 4 29 -30 48 41 -32 48 34 -30 7 42
134 0 0 -31 42 41 14 52 6 6 60 -45 -32 21 15 -31 5 2 -33 5 35 -30 23 50
133 0 0 -32 0 29 14 52 1 5 61 -45 -32 39 16 -31 22 36 -33 23 54 -30 41 11
132 0 0 -32 19 31 14 51 57 4 61 -45 -32 58 35 -31 41 24 -33 43 32 .. .. ..
131 0 0 -32 39 48 14 51 54 3 62 -44 -33 19 9 -32 1 25 -34 4 28 .. .. ..
Uncertainty in time = +/- 9 secs
Prediction of 2011 Oct 14.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
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