|
|
Updated: 2011 JAN 27, 10:29 UT
Event Rank : 97
(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 Feb 25 UT, the 96 km diameter asteroid (554) Peraga will occult a 12.8 mag star in the constellation Gemini for observers along a path firstly passing over Canberra, and then in New Zealand near Haast and Timaru.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.7 mag to 12.6 mag (the magnitude of the asteroid) for at most 15.5 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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
-174 45 30 -53 0 0 10 3 28 8 326 -24 -176 33 30 -172 59 8 -177 56 48 -171 39 15
-176 23 57 -52 0 0 10 3 21 9 328 -24 -178 11 1 -174 38 37 -179 33 40 -173 19 36
-178 2 54 -51 0 0 10 3 13 10 329 -24 -179 49 14 -176 18 23 178 48 34 -175 0 3
-179 42 33 -50 0 0 10 3 4 12 330 -25 178 31 35 -177 58 38 177 9 40 -176 40 50
178 36 50 -49 0 0 10 2 53 13 332 -25 176 51 12 -179 39 38 175 29 23 -178 22 12
176 55 0 -48 0 0 10 2 41 15 333 -25 175 9 22 178 38 23 173 47 25 179 55 38
175 11 40 -47 0 0 10 2 28 16 335 -25 173 25 45 176 55 11 172 3 28 178 12 24
173 26 33 -46 0 0 10 2 13 17 336 -25 171 40 4 175 10 26 170 17 11 176 27 49
171 39 17 -45 0 0 10 1 56 19 338 -25 169 51 54 173 23 51 168 28 8 174 41 36
169 49 30 -44 0 0 10 1 38 20 340 -24 168 0 49 171 35 3 166 35 52 172 53 25
167 56 43 -43 0 0 10 1 17 22 341 -24 166 6 19 169 43 39 164 39 48 171 2 53
166 0 24 -42 0 0 10 0 55 23 343 -23 164 7 46 167 49 10 162 39 12 169 9 33
163 59 54 -41 0 0 10 0 30 25 345 -23 162 4 23 165 51 1 160 33 13 167 12 54
Latitude Latitude Latitude Latitude
162 0 0 -40 2 38 10 0 4 26 347 -22 -40 57 55 -39 8 51 -41 41 2 -38 28 54
161 0 0 -39 34 50 9 59 51 26 348 -21 -40 29 43 -38 41 24 -41 12 31 -38 1 43
160 0 0 -39 7 39 9 59 37 27 349 -21 -40 2 10 -38 14 35 -40 44 40 -37 35 8
159 0 0 -38 41 8 9 59 23 28 350 -20 -39 35 17 -37 48 24 -40 17 28 -37 9 11
158 0 0 -38 15 16 9 59 8 28 351 -20 -39 9 3 -37 22 51 -39 50 56 -36 43 53
157 0 0 -37 50 4 9 58 54 29 352 -19 -38 43 30 -36 57 59 -39 25 6 -36 19 14
156 0 0 -37 25 32 9 58 39 29 353 -19 -38 18 39 -36 33 46 -38 59 59 -35 55 15
155 0 0 -37 1 43 9 58 24 30 355 -18 -37 54 30 -36 10 15 -38 35 34 -35 31 57
154 0 0 -36 38 36 9 58 9 30 356 -18 -37 31 4 -35 47 25 -38 11 52 -35 9 20
153 0 0 -36 16 12 9 57 53 31 357 -17 -37 8 21 -35 25 18 -37 48 55 -34 47 25
152 0 0 -35 54 31 9 57 38 31 358 -17 -36 46 23 -35 3 54 -37 26 42 -34 26 12
151 0 0 -35 33 34 9 57 22 31 359 -16 -36 25 9 -34 43 13 -37 5 14 -34 5 43
150 0 0 -35 13 22 9 57 6 32 0 -15 -36 4 41 -34 23 16 -36 44 33 -33 45 57
149 0 0 -34 53 55 9 56 50 32 1 -15 -35 44 58 -34 4 4 -36 24 37 -33 26 55
148 0 0 -34 35 14 9 56 33 32 2 -14 -35 26 1 -33 45 36 -36 5 28 -33 8 38
147 0 0 -34 17 18 9 56 17 33 4 -13 -35 7 51 -33 27 54 -35 47 6 -32 51 5
146 0 0 -34 0 8 9 56 1 33 5 -12 -34 50 27 -33 10 58 -35 29 31 -32 34 18
145 0 0 -33 43 45 9 55 44 33 6 -12 -34 33 51 -32 54 47 -35 12 44 -32 18 16
144 0 0 -33 28 9 9 55 27 33 7 -11 -34 18 2 -32 39 23 -34 56 45 -32 3 0
143 0 0 -33 13 20 9 55 11 33 8 -10 -34 3 1 -32 24 45 -34 41 34 -31 48 30
142 0 0 -32 59 18 9 54 54 33 10 -9 -33 48 48 -32 10 54 -34 27 12 -31 34 47
141 0 0 -32 46 4 9 54 37 33 11 -9 -33 35 23 -31 57 50 -34 13 39 -31 21 50
140 0 0 -32 33 38 9 54 21 33 12 -8 -33 22 47 -31 45 33 -34 0 54 -31 9 40
139 0 0 -32 22 0 9 54 4 33 13 -7 -33 10 59 -31 34 4 -33 48 59 -30 58 18
138 0 0 -32 11 10 9 53 47 33 14 -6 -33 0 0 -31 23 22 -33 37 52 -30 47 42
137 0 0 -32 1 8 9 53 31 33 15 -5 -32 49 50 -31 13 28 -33 27 35 -30 37 53
136 0 0 -31 51 54 9 53 14 33 17 -4 -32 40 29 -31 4 22 -33 18 8 -30 28 52
135 0 0 -31 43 29 9 52 58 33 18 -4 -32 31 56 -30 56 3 -33 9 30 -30 20 39
134 0 0 -31 35 52 9 52 41 33 19 -3 -32 24 13 -30 48 33 -33 1 41 -30 13 13
133 0 0 -31 29 4 9 52 25 33 20 -2 -32 17 19 -30 41 50 -32 54 43 -30 6 34
132 0 0 -31 23 5 9 52 9 32 21 -1 -32 11 14 -30 35 55 -32 48 33 -30 0 43
131 0 0 -31 17 53 9 51 53 32 22 0 -32 5 58 -30 30 49 -32 43 14 -29 55 40
Uncertainty in time = +/- 6 secs
Prediction of 2011 Jan 27.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
[Asteroid Occultation Results]
[Top of Page][Return to Home Page]