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Updated: 2005 MAY 03, 00:25 UT
Event Rank : 45
(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 2005 May 24 UT (before dawn on the 25th), the 26 km diameter asteroid (1108) Demeter will occult a 9.0 mag star in the constellation Pegasus for observers along a path across New Zealand.
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.8 mag to 15.8 mag (the magnitude of the asteroid) for at most 0.9 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
155 12 13 -71 0 0 18 56 2 0 14 -23 155 42 33 154 41 54 157 11 16 153 13 28
155 58 59 -70 0 0 18 56 2 1 13 -23 156 27 53 155 30 6 157 52 25 154 5 51
156 44 20 -69 0 0 18 56 3 3 13 -22 157 11 57 156 16 44 158 32 43 154 56 16
157 28 29 -68 0 0 18 56 3 4 12 -22 157 54 56 157 2 3 159 12 19 155 44 59
158 11 36 -67 0 0 18 56 3 5 11 -22 158 37 0 157 46 14 159 51 18 156 32 16
158 53 52 -66 0 0 18 56 4 6 11 -21 159 18 18 158 29 28 160 29 47 157 18 19
159 35 24 -65 0 0 18 56 4 7 10 -21 159 58 57 159 11 53 161 7 52 158 3 18
160 16 18 -64 0 0 18 56 5 8 9 -21 160 39 3 159 53 35 161 45 37 158 47 23
160 56 41 -63 0 0 18 56 6 9 9 -20 161 18 41 160 34 43 162 23 5 159 30 40
161 36 37 -62 0 0 18 56 7 10 8 -20 161 57 56 161 15 20 163 0 20 160 13 17
162 16 11 -61 0 0 18 56 8 11 8 -19 162 36 52 161 55 32 163 37 26 160 55 20
162 55 27 -60 0 0 18 56 9 12 7 -19 163 15 33 162 35 22 164 14 24 161 36 53
163 34 28 -59 0 0 18 56 10 13 6 -19 163 54 2 163 14 56 164 51 18 162 18 1
164 13 17 -58 0 0 18 56 11 14 6 -18 164 32 21 163 54 15 165 28 9 162 58 49
164 51 58 -57 0 0 18 56 13 15 5 -17 165 10 34 164 33 24 166 5 0 163 39 19
165 30 33 -56 0 0 18 56 14 16 5 -17 165 48 43 165 12 25 166 41 53 164 19 37
166 9 5 -55 0 0 18 56 16 17 4 -16 166 26 50 165 51 21 167 18 49 164 59 43
166 47 35 -54 0 0 18 56 18 18 3 -16 167 4 57 166 30 14 167 55 51 165 39 42
167 26 6 -53 0 0 18 56 19 19 3 -15 167 43 8 167 9 6 168 32 59 166 19 36
168 4 40 -52 0 0 18 56 21 20 2 -14 168 21 22 167 48 0 169 10 16 166 59 27
168 43 19 -51 0 0 18 56 23 21 1 -14 168 59 43 168 26 57 169 47 43 167 39 18
169 22 5 -50 0 0 18 56 25 22 1 -13 169 38 12 169 6 0 170 25 22 168 19 12
170 1 0 -49 0 0 18 56 28 23 0 -12 170 16 50 169 45 11 171 3 14 168 59 9
170 40 5 -48 0 0 18 56 30 24 359 -12 170 55 40 170 24 31 171 41 21 169 39 12
171 19 22 -47 0 0 18 56 33 25 359 -11 171 34 43 171 4 1 172 19 43 170 19 23
171 58 52 -46 0 0 18 56 35 26 358 -10 172 14 1 171 43 45 172 58 24 170 59 45
172 38 38 -45 0 0 18 56 38 27 357 -9 172 53 35 172 23 43 173 37 23 171 40 18
173 18 42 -44 0 0 18 56 40 28 356 -9 173 33 27 173 3 58 174 16 43 172 21 5
173 59 4 -43 0 0 18 56 43 29 356 -8 174 13 39 173 44 30 174 56 25 173 2 7
174 39 47 -42 0 0 18 56 46 30 355 -7 174 54 13 174 25 22 175 36 31 173 43 27
175 20 52 -41 0 0 18 56 49 31 354 -6 175 35 9 175 6 36 176 17 2 174 25 7
176 2 21 -40 0 0 18 56 52 32 353 -5 176 16 30 175 48 13 176 58 0 175 7 7
176 44 16 -39 0 0 18 56 56 33 352 -4 176 58 18 176 30 16 177 39 27 175 49 31
177 26 39 -38 0 0 18 56 59 34 351 -3 177 40 35 177 12 45 178 21 25 176 32 20
178 9 32 -37 0 0 18 57 3 35 350 -2 178 23 22 177 55 44 179 3 55 177 15 35
178 52 56 -36 0 0 18 57 6 35 349 -2 179 6 41 178 39 13 179 46 59 177 59 20
179 36 55 -35 0 0 18 57 10 36 348 -1 179 50 35 179 23 16 -179 29 20 178 43 36
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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