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Updated: 2009 SEP 17, 22:20 UT
Event Rank : 21
(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 2009 Oct 15 UT, the 39 km diameter asteroid (1102) Pepita will occult a 11.6 mag star in the constellation Monoceros for observers along a significant uncertainty path running from Port Hedland in northern West Australia, across South Australia, western NSW, across Victoria from Mildura to Queenscliff, near Geelong and over western Tasmania.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.5 mag to 15.1 mag (the magnitude of the asteroid) for at most 3.1 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
146 30 2 -45 0 0 16 13 32 20 52 -29 145 52 25 147 7 0 141 28 35 150 53 31
146 22 37 -44 0 0 16 13 24 20 53 -29 145 45 29 146 59 6 141 25 13 150 42 47
146 12 9 -43 0 0 16 13 16 21 53 -30 145 35 25 146 48 14 141 18 3 150 29 32
145 58 43 -42 0 0 16 13 8 21 54 -31 145 22 19 146 34 30 141 7 10 150 13 49
145 42 24 -41 0 0 16 13 0 22 54 -32 145 6 15 146 17 56 140 52 42 149 55 42
145 23 14 -40 0 0 16 12 51 22 55 -33 144 47 14 145 58 35 140 34 39 149 35 12
145 1 13 -39 0 0 16 12 43 22 55 -34 144 25 18 145 36 29 140 13 3 149 12 20
144 36 21 -38 0 0 16 12 34 23 56 -35 144 0 27 145 11 36 139 47 52 148 47 7
144 8 37 -37 0 0 16 12 24 23 57 -36 143 32 39 144 43 56 139 19 1 148 19 32
143 37 58 -36 0 0 16 12 15 23 58 -37 143 1 49 144 13 24 138 46 25 147 49 32
143 4 17 -35 0 0 16 12 5 23 59 -38 142 27 54 143 39 58 138 9 52 147 17 5
142 27 29 -34 0 0 16 11 56 23 59 -39 141 50 44 143 3 29 137 29 9 146 42 7
141 47 25 -33 0 0 16 11 46 23 60 -40 141 10 11 142 23 51 136 43 58 146 4 32
141 3 52 -32 0 0 16 11 35 23 61 -42 140 26 1 141 40 52 135 53 53 145 24 13
140 16 36 -31 0 0 16 11 25 23 62 -43 139 37 59 140 54 18 134 58 22 144 41 2
139 25 17 -30 0 0 16 11 14 23 63 -44 138 45 43 140 3 52 133 56 40 143 54 47
138 29 33 -29 0 0 16 11 3 22 64 -45 137 48 48 139 9 12 132 47 44 143 5 17
137 28 51 -28 0 0 16 10 51 22 65 -47 136 46 37 138 9 50 131 30 4 142 12 13
136 22 30 -27 0 0 16 10 40 22 66 -48 135 38 24 137 5 9 130 1 24 141 15 17
135 9 34 -26 0 0 16 10 28 21 67 -50 134 23 6 135 54 20 128 17 57 140 14 2
133 48 46 -25 0 0 16 10 15 20 68 -51 132 59 12 134 36 15 126 12 38 139 7 57
132 18 12 -24 0 0 16 10 3 19 70 -53 131 24 27 133 9 19 123 28 33 137 56 17
130 34 57 -23 0 0 16 9 49 18 71 -54 129 35 9 131 31 7 118 44 40 136 38 8
128 33 56 -22 0 0 16 9 35 16 72 -56 127 24 35 129 37 41 ... .. .. 135 12 12
127 0 0 -21 20 29 16 9 25 15 73 -57 -21 50 2 -20 51 34 -25 21 9 -17 56 30
126 0 0 -20 58 16 16 9 20 14 74 -58 -21 27 22 -20 29 46 -24 54 40 -17 36 55
125 0 0 -20 38 19 16 9 14 14 74 -59 -21 7 2 -20 10 11 -24 30 59 -17 19 17
124 0 0 -20 20 34 16 9 9 13 75 -59 -20 48 56 -19 52 46 -24 9 59 -17 3 34
123 0 0 -20 4 57 16 9 5 12 75 -60 -20 33 1 -19 37 25 -23 51 33 -16 49 45
122 0 0 -19 51 25 16 9 0 11 75 -60 -20 19 14 -19 24 8 -23 35 36 -16 37 46
121 0 0 -19 39 55 16 8 56 10 76 -61 -20 7 31 -19 12 51 -23 22 3 -16 27 36
120 0 0 -19 30 26 16 8 53 9 76 -61 -19 57 50 -19 3 32 -23 10 50 .. .. ..
119 0 0 -19 22 54 16 8 50 8 77 -62 -19 50 10 -18 56 9 -23 1 55 .. .. ..
118 0 0 -19 17 19 16 8 47 7 77 -62 -19 44 27 -18 50 40 -22 55 15 .. .. ..
117 0 0 -19 13 39 16 8 44 7 77 -62 -19 40 42 -18 47 5 -22 50 47 .. .. ..
116 0 0 -19 11 53 16 8 42 6 78 -62 -19 38 53 -18 45 22 -22 48 30 .. .. ..
115 0 0 -19 12 1 16 8 40 5 78 -62 -19 38 59 -18 45 31 -22 48 23 .. .. ..
114 0 0 -19 14 1 16 8 38 4 78 -62 -19 41 0 -18 47 31 -22 50 26 .. .. ..
113 0 0 -19 17 54 16 8 37 3 79 -62 -19 44 55 -18 51 23 -22 54 38 .. .. ..
Uncertainty in time = +/- 10 secs
Prediction of 2009 Sep 18.0
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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