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Updated: 2018 NOV 24, 05:57 UT
Event Rank : 99
(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 2019 Jan 04 UT, the 100.3 km diameter asteroid (227) Philosophia will occult a 10.9 mag star in the constellation Auriga for observers along a broad path across south-eastern Australia from Ballina across north-eastern to southern New South Wales and western Victoria to Portland, and including Bendigo.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.72 mag to 14.57 mag (the magnitude of the asteroid) for at most 7.1 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, astrometry for the asteroid kindly provided by Bill Owen, astrometry for the asteroid kindly provided by the IAU Minor Planet Center.
This work has made use of data from the European Space Agency (ESA) mission Gaia (http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, http://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.
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 Alt
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 Crn
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
138 47 4 -41 0 0 11 46 17 13 17 -14 137 26 23 140 9 30 136 47 39 140 50 19 1.41
139 48 44 -40 0 0 11 46 13 14 16 -15 138 27 55 141 11 20 137 49 9 141 52 16 1.42
140 52 16 -39 0 0 11 46 8 16 15 -16 139 31 13 142 15 11 138 52 21 142 56 19 1.43
141 57 49 -38 0 0 11 46 3 17 15 -17 140 36 23 143 21 12 139 57 22 144 2 36 1.43
143 5 31 -37 0 0 11 45 58 18 14 -19 141 43 34 144 29 32 141 4 20 145 11 16 1.43
144 15 32 -36 0 0 11 45 52 19 13 -20 142 52 54 145 40 21 142 13 23 146 22 32 1.44
145 28 4 -35 0 0 11 45 45 20 12 -21 144 4 35 146 53 52 143 24 41 147 36 36 1.44
146 43 19 -34 0 0 11 45 38 21 11 -23 145 18 46 148 10 20 144 38 25 148 53 43 1.44
148 1 32 -33 0 0 11 45 31 23 10 -24 146 35 44 149 30 2 145 54 49 150 14 13 1.45
149 23 3 -32 0 0 11 45 22 24 9 -26 147 55 43 150 53 19 147 14 7 151 38 27 1.45
150 48 12 -31 0 0 11 45 13 25 8 -27 149 19 2 152 20 35 148 36 38 153 6 53 1.45
152 17 26 -30 0 0 11 45 4 26 6 -29 150 46 4 153 52 21 150 2 43 154 40 2 1.45
153 51 16 -29 0 0 11 44 54 27 5 -30 152 17 17 155 29 15 151 32 47 156 18 37 1.45
155 30 23 -28 0 0 11 44 42 28 3 -32 153 53 15 157 12 5 153 7 23 158 3 30 1.45
157 15 38 -27 0 0 11 44 30 29 2 -34 155 34 39 159 1 54 154 47 7 159 55 53 1.45
159 8 7 -26 0 0 11 44 17 30 0 -35 157 22 24 161 0 7 156 32 51 161 57 21 1.45
-133 0 0 .. .. .. .. .. .. .. .. .. -31 19 23 .. .. .. .. .. .. .. .. .. ....
Uncertainty in time = +/- 3 secs
Prediction of 2018 Nov 24.0
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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