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Updated: 2008 MAR 31, 04:42 UT
Event Rank : 61
(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 2008 May 12 UT, the 43 km diameter asteroid (132) Aethra will occult a 12.4 mag star in the constellation Sagittarius for observers along a path across the South Island New Zealand beginning between Dunedin and Invercargill. The path moves north-west centred between Queenstown and Wanaka. Later the path moves into Australia over Cairns, but at this time the event is at quite low altitude.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.1 mag to 13.1 mag (the magnitude of the asteroid) for at most 3.8 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 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
171 10 1 -49 12 6 11 18 56 39 86 -56 170 42 11 -49 14 50 171 37 36 -49 9 15 169 45 14 -49 20 4 172 32 38 -49 3 13
170 44 52 -48 18 8 11 19 5 39 87 -56 170 17 26 -48 20 47 171 12 3 -48 15 23 169 21 19 -48 25 50 172 6 17 -48 9 31
170 18 49 -47 24 9 11 19 14 38 88 -57 169 51 46 -47 26 43 170 45 38 -47 21 29 168 56 24 -47 31 34 171 39 9 -47 15 48
169 51 53 -46 30 7 11 19 23 38 89 -58 169 25 10 -46 32 35 170 18 22 -46 27 33 168 30 31 -46 37 16 171 11 13 -46 22 3
169 24 4 -45 36 1 11 19 32 38 90 -58 168 57 39 -45 38 23 169 50 14 -45 33 32 168 3 38 -45 42 52 170 42 28 -45 28 15
168 55 20 -44 41 48 11 19 41 38 91 -59 168 29 13 -44 44 5 169 21 14 -44 39 26 167 35 46 -44 48 21 170 12 55 -44 34 21
168 25 42 -43 47 28 11 19 50 37 92 -59 167 59 50 -43 49 38 168 51 21 -43 45 12 167 6 55 -43 53 42 169 42 32 -43 40 19
167 55 9 -42 52 59 11 19 59 37 93 -60 167 29 30 -42 55 2 168 20 34 -42 50 49 166 37 2 -42 58 52 169 11 18 -42 46 10
167 23 38 -41 58 18 11 20 8 36 94 -60 166 58 11 -42 0 14 167 48 52 -41 56 15 166 6 7 -42 3 50 168 39 11 -41 51 49
166 51 8 -41 3 23 11 20 17 36 95 -60 166 25 52 -41 5 12 167 16 12 -41 1 27 165 34 8 -41 8 34 168 6 10 -40 57 16
166 17 37 -40 8 13 11 20 26 36 96 -61 165 52 29 -40 9 55 166 42 32 -40 6 25 165 1 3 -40 13 0 167 32 13 -40 2 28
165 43 2 -39 12 45 11 20 35 35 97 -61 165 18 2 -39 14 18 166 7 50 -39 11 4 164 26 49 -39 17 8 166 57 17 -39 7 23
165 7 21 -38 16 56 11 20 44 35 98 -61 164 42 25 -38 18 21 165 32 3 -38 15 24 163 51 22 -38 20 53 166 21 19 -38 11 59
164 30 29 -37 20 44 11 20 53 34 99 -61 164 5 37 -37 22 0 164 55 8 -37 19 21 163 14 40 -37 24 13 165 44 15 -37 16 13
163 52 22 -36 24 5 11 21 3 33 100 -62 163 27 31 -36 25 12 164 16 59 -36 22 52 162 36 37 -36 27 5 165 6 3 -36 20 3
163 12 56 -35 26 58 11 21 12 33 100 -62 162 48 5 -35 27 54 163 37 33 -35 25 54 161 57 8 -35 29 26 164 26 36 -35 23 25
162 32 5 -34 29 17 11 21 21 32 101 -62 162 7 11 -34 30 2 162 56 45 -34 28 24 161 16 8 -34 31 11 163 45 51 -34 26 16
161 49 42 -33 30 58 11 21 30 31 102 -62 161 24 43 -33 31 32 162 14 27 -33 30 17 160 33 28 -33 32 16 163 3 41 -33 28 32
161 5 40 -32 31 58 11 21 39 30 103 -61 160 40 33 -32 32 19 161 30 32 -32 31 30 159 49 0 -32 32 35 162 19 59 -32 30 9
160 19 50 -31 32 10 11 21 48 30 104 -61 159 54 32 -31 32 17 160 44 51 -31 31 56 159 2 35 -31 32 3 161 34 37 -31 31 2
159 32 0 -30 31 29 11 21 57 29 105 -61 159 6 28 -30 31 20 159 57 15 -30 31 30 158 14 0 -30 30 33 160 47 25 -30 31 5
158 41 58 -29 29 48 11 22 6 28 106 -61 158 16 8 -29 29 21 159 7 30 -29 30 5 157 23 0 -29 27 57 159 58 11 -29 30 13
157 49 29 -28 26 57 11 22 15 27 106 -60 157 23 16 -28 26 10 158 15 22 -28 27 33 156 29 17 -28 24 4 159 6 43 -28 28 17
156 54 13 -27 22 46 11 22 24 26 107 -60 156 27 31 -27 21 37 157 20 33 -27 23 44 155 32 29 -27 18 43 158 12 44 -27 25 8
155 55 46 -26 17 3 11 22 33 25 108 -59 155 28 29 -26 15 29 156 22 40 -26 18 25 154 32 7 -26 11 39 157 15 53 -26 20 37
154 53 39 -25 9 32 11 22 42 23 109 -58 154 25 37 -25 7 28 155 21 14 -25 11 23 153 27 36 -25 2 33 156 15 44 -25 14 28
153 47 11 -23 59 52 11 22 51 22 110 -57 153 18 13 -23 57 12 154 15 39 -24 2 17 152 18 5 -23 50 58 155 11 46 -24 6 25
152 35 30 -22 47 37 11 23 0 21 110 -56 152 5 20 -22 44 13 153 5 6 -22 50 42 151 2 28 -22 36 22 154 3 16 -22 56 7
151 17 23 -21 32 8 11 23 9 19 111 -55 150 45 37 -21 27 49 151 48 27 -21 36 5 149 39 6 -21 17 54 152 49 16 -21 43 3
149 51 2 -20 12 31 11 23 18 17 112 -54 149 17 6 -20 7 0 150 24 5 -20 17 34 148 5 28 -19 54 18 151 28 25 -20 26 32
148 13 36 -18 47 20 11 23 27 16 113 -52 147 36 31 -18 40 9 148 49 28 -18 53 55 146 17 18 -18 23 25 149 58 42 -19 5 34
146 20 10 -17 14 8 11 23 36 13 113 -50 145 38 6 -17 4 21 147 0 23 -17 23 0 144 6 7 -16 41 1 148 16 54 -17 38 30
144 0 26 -15 27 49 11 23 45 11 114 -48 143 8 55 -15 13 12 144 48 26 -15 40 39 141 9 14 -14 35 55 146 17 10 -16 2 27
140 43 42 -13 13 10 11 23 55 7 115 -44 139 22 36 -12 43 50 141 51 35 -13 35 57 ... .. .. .. .. .. 143 46 34 -14 10 58
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