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Updated: 2007 AUG 29, 00:57 UT
Event Rank : 59
(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 2007 Sep 08 UT, the 69 km diameter asteroid (174) Phaedra will occult a 11.7 mag star in the constellation Sagittarius for observers along a path across Australia from south-eastern Western Australia to southern Northern Territory at decreasing altitude.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.6 mag to 13.1 mag (the magnitude of the asteroid) for at most 5.6 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
124 59 11 -33 44 11 16 9 15 23 247 -61 124 10 51 -33 51 7 125 48 40 -33 36 28 122 31 44 -34 3 30 127 37 42 -33 17 14
125 52 10 -32 33 27 16 9 24 22 246 -62 125 2 47 -32 41 23 126 42 49 -32 24 38 123 21 49 -32 55 39 128 34 57 -32 2 41
126 49 23 -31 20 4 16 9 32 21 245 -63 125 58 38 -31 29 13 127 41 35 -31 9 56 124 15 18 -31 45 41 129 37 47 -30 44 39
127 51 42 -30 3 29 16 9 40 20 244 -64 126 59 11 -30 14 6 128 45 57 -29 51 43 125 12 45 -30 33 14 130 47 39 -29 22 12
129 0 22 -28 42 54 16 9 48 18 243 -64 128 5 28 -28 55 21 129 57 23 -28 29 2 126 14 57 -29 17 45 132 6 45 -27 53 55
130 17 13 -27 17 7 16 9 56 16 242 -65 129 19 1 -27 31 58 131 18 8 -27 0 26 127 23 1 -27 58 33 133 38 50 -26 17 23
131 45 13 -25 44 13 16 10 4 14 242 -65 130 42 15 -26 2 27 132 52 0 -25 23 29 128 38 33 -26 34 34 135 31 8 -24 27 59
133 29 45 -24 0 48 16 10 12 12 241 -66 132 19 13 -24 24 9 134 46 24 -23 33 28 130 4 4 -25 4 13 138 2 25 -22 13 50
135 42 44 -21 59 17 16 10 20 9 240 -66 134 18 2 -22 31 56 137 20 32 -21 18 13 131 43 52 -23 24 44 143 54 21 -17 52 55
139 6 58 -19 12 40 16 10 28 5 238 -64 137 0 44 -20 11 54 ... .. .. .. .. .. 133 46 46 -21 30 33 ... .. .. .. .. ..
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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