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Updated: 2008 JAN 11, 02:18 UT
Event Rank : 16
(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 Jan 15 UT, the 87 km diameter asteroid (227) Philosophia will occult a 9.8 mag star in the constellation Auriga for observers along a wide and very large uncertainty path across south-eastern Australia, centered over eastern Victoria.
In the case of an occultation, the combined light of the asteroid and the star will drop by 4.2 mag to 13.9 mag (the magnitude of the asteroid) for at most 6.2 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
137 36 54 -45 0 0 12 3 51 10 18 -13 136 5 20 139 11 26 ... .. .. 156 10 26
138 44 51 -44 0 0 12 3 47 11 17 -14 137 12 42 140 20 6 ... .. .. 157 43 56
139 55 55 -43 0 0 12 3 43 12 16 -15 138 22 57 141 32 10 ... .. .. 159 28 49
141 10 23 -42 0 0 12 3 38 14 15 -17 139 36 21 142 47 57 ... .. .. 161 28 20
142 28 33 -41 0 0 12 3 32 15 14 -18 140 53 7 144 7 47 ... .. .. 163 48 4
143 50 47 -40 0 0 12 3 25 16 13 -20 142 13 37 145 32 7 ... .. .. 166 39 14
145 17 34 -39 0 0 12 3 18 17 12 -21 143 38 13 147 1 31 ... .. .. 170 32 58
146 49 28 -38 0 0 12 3 10 18 11 -23 145 7 26 148 36 40 ... .. .. ... .. ..
148 27 14 -37 0 0 12 3 1 20 10 -24 146 41 51 150 18 30 ... .. .. ... .. ..
150 11 50 -36 0 0 12 2 51 21 8 -26 148 22 17 152 8 15 ... .. .. ... .. ..
152 4 34 -35 0 0 12 2 40 22 7 -27 150 9 44 154 7 38 136 59 49 ... .. ..
154 7 16 -34 0 0 12 2 27 23 5 -29 152 5 36 156 19 9 138 29 22 ... .. ..
155 0 0 -33 35 52 12 2 22 24 4 -30 -32 38 33 -34 35 21 -25 32 7 -45 49 48
156 0 0 -33 9 35 12 2 15 24 3 -30 -32 12 55 -34 8 21 -25 10 11 -45 7 7
157 0 0 -32 44 32 12 2 9 25 2 -31 -31 48 28 -33 42 38 -24 49 14 -44 27 23
158 0 0 -32 20 43 12 2 2 25 1 -32 -31 25 13 -33 18 11 -24 29 15 -43 50 20
159 0 0 -31 58 6 12 1 56 25 0 -33 -31 3 8 -32 54 59 -24 10 14 -43 15 46
160 0 0 -31 36 40 12 1 49 26 360 -33 -30 42 11 -32 33 0 -23 52 11 -42 43 32
161 0 0 -31 16 25 12 1 43 26 359 -34 -30 22 24 -32 12 15 -23 35 5 -42 13 28
162 0 0 -30 57 20 12 1 36 26 358 -35 -30 3 44 -31 52 42 -23 18 55 -41 45 29
163 0 0 -30 39 24 12 1 29 27 357 -35 -29 46 11 -31 34 20 -23 3 43 -41 19 28
164 0 0 -30 22 36 12 1 22 27 356 -36 -29 29 45 -31 17 8 -22 49 27 -40 55 21
165 0 0 -30 6 56 12 1 16 27 355 -36 -29 14 25 -31 1 7 -22 36 7 -40 33 3
166 0 0 -29 52 24 12 1 9 27 354 -37 -29 0 11 -30 46 14 -22 23 44 -40 12 30
167 0 0 -29 38 58 12 1 2 27 353 -37 -28 47 3 -30 32 30 -22 12 16 -39 53 40
168 0 0 -29 26 39 12 0 55 27 352 -38 -28 34 59 -30 19 55 -22 1 44 -39 36 30
169 0 0 -29 15 26 12 0 48 28 351 -38 -28 23 59 -30 8 26 -21 52 7 -39 20 57
170 0 0 -29 5 18 12 0 41 28 350 -39 -28 14 4 -29 58 5 -21 43 26 -39 7 0
171 0 0 -28 56 16 12 0 35 28 349 -39 -28 5 12 -29 48 51 -21 35 41 -38 54 36
172 0 0 -28 48 19 12 0 28 28 349 -39 -27 57 24 -29 40 44 -21 28 50 -38 43 45
173 0 0 -28 41 27 12 0 21 27 348 -39 -27 50 40 -29 33 43 -21 22 55 -38 34 25
174 0 0 -28 35 39 12 0 14 27 347 -40 -27 44 59 -29 27 48 -21 17 55 -38 26 35
175 0 0 -28 30 55 12 0 8 27 346 -40 -27 40 21 -29 22 58 -21 13 49 -38 20 13
176 0 0 -28 27 16 12 0 1 27 345 -40 -27 36 45 -29 19 15 -21 10 39 -38 15 21
177 0 0 -28 24 41 11 59 54 27 344 -40 -27 34 13 -29 16 37 -21 8 23 -38 11 56
178 0 0 -28 23 11 11 59 48 27 343 -40 -27 32 44 -29 15 5 -21 7 3 -38 10 0
179 0 0 -28 22 44 11 59 41 26 342 -40 -27 32 18 -29 14 38 -21 6 37 -38 9 31
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
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[Asteroid Occultation Results]
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