|
|
Updated: 2008 OCT 30, 13:55 UT
Event Rank : 50
(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 Nov 04 UT, the 40 km diameter asteroid (155) Scylla will occult a 12.5 mag star in the constellation Taurus for observers along a fairly narrow path across Australia from Warnambool in Victoria, crossing western New South Wales, northeastern South Australia and south-western Queensland to the Northern Territory close to Darwin. (Melbourne is just on the one sigma limit)
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.7 mag to 14.0 mag (the magnitude of the asteroid) for at most 6.3 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 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 57 52 -48 0 0 13 37 51 3 38 -25 138 43 6 137 11 23 ... .. .. 135 4 46
138 48 17 -47 0 0 13 37 54 4 38 -27 139 31 24 138 4 5 ... .. .. 136 4 19
139 31 39 -46 0 0 13 37 58 6 37 -28 140 12 57 138 49 23 141 55 31 136 55 16
140 8 48 -45 0 0 13 38 3 7 37 -29 140 48 34 139 28 10 142 27 31 137 38 50
140 40 25 -44 0 0 13 38 8 8 36 -30 141 18 50 140 1 11 142 54 40 138 15 55
141 7 1 -43 0 0 13 38 14 9 36 -31 141 44 18 140 29 1 143 17 23 138 47 14
141 29 5 -42 0 0 13 38 21 10 36 -32 142 5 20 140 52 9 143 36 1 139 13 23
141 46 57 -41 0 0 13 38 28 11 36 -33 142 22 20 141 10 57 143 50 54 139 34 49
142 0 57 -40 0 0 13 38 36 12 36 -34 142 35 33 141 25 46 144 2 15 139 51 55
142 11 21 -39 0 0 13 38 45 12 36 -35 142 45 15 141 36 52 144 10 19 140 5 0
142 18 20 -38 0 0 13 38 54 13 36 -36 142 51 39 141 44 28 144 15 15 140 14 21
142 22 6 -37 0 0 13 39 4 14 36 -37 142 54 54 141 48 47 144 17 15 140 20 9
142 22 49 -36 0 0 13 39 14 15 36 -38 142 55 9 141 49 58 144 16 24 140 22 38
142 20 36 -35 0 0 13 39 25 16 36 -39 142 52 33 141 48 9 144 12 51 140 21 54
142 15 33 -34 0 0 13 39 36 17 36 -40 142 47 11 141 43 26 144 6 41 140 18 7
142 7 46 -33 0 0 13 39 48 17 37 -41 142 39 7 141 35 55 143 57 58 140 11 21
141 57 18 -32 0 0 13 40 1 18 37 -42 142 28 27 141 25 41 143 46 45 140 1 42
141 44 14 -31 0 0 13 40 14 19 37 -43 142 15 13 141 12 46 143 33 6 139 49 13
141 28 33 -30 0 0 13 40 27 20 37 -44 141 59 26 140 57 12 143 17 3 139 33 56
141 10 19 -29 0 0 13 40 41 20 38 -45 141 41 8 140 39 1 142 58 35 139 15 52
140 49 31 -28 0 0 13 40 56 21 38 -45 141 20 20 140 18 13 142 37 45 138 55 2
140 26 8 -27 0 0 13 41 11 21 39 -46 140 57 0 139 54 46 142 14 31 138 31 24
140 0 8 -26 0 0 13 41 27 22 39 -47 140 31 6 139 28 40 141 48 51 138 4 55
139 31 29 -25 0 0 13 41 44 23 40 -48 140 2 37 138 59 50 141 20 44 137 35 33
139 0 6 -24 0 0 13 42 1 23 40 -49 139 31 28 138 28 12 140 50 6 137 3 12
138 25 55 -23 0 0 13 42 18 23 41 -50 138 57 35 137 53 42 140 16 53 136 27 44
137 48 48 -22 0 0 13 42 37 24 42 -51 138 20 50 137 16 11 139 41 0 135 49 3
137 8 37 -21 0 0 13 42 56 24 42 -51 137 41 6 136 35 30 139 2 19 135 6 55
136 25 11 -20 0 0 13 43 15 25 43 -52 136 58 14 135 51 29 138 20 43 134 21 8
135 38 17 -19 0 0 13 43 36 25 44 -53 136 12 0 135 3 52 137 36 1 133 31 24
134 47 40 -18 0 0 13 43 57 25 45 -53 135 22 10 134 12 23 136 48 0 132 37 21
133 52 57 -17 0 0 13 44 19 25 46 -54 134 28 26 133 16 38 135 56 26 131 38 30
132 53 45 -16 0 0 13 44 42 25 46 -54 133 30 23 132 16 11 135 0 58 130 34 16
131 49 30 -15 0 0 13 45 6 25 47 -55 132 27 31 131 10 24 134 1 14 129 23 48
130 39 29 -14 0 0 13 45 31 25 48 -55 131 19 13 129 58 30 132 56 42 128 6 0
129 22 44 -13 0 0 13 45 57 25 49 -55 130 4 36 128 39 23 131 46 45 126 39 17
127 57 56 -12 0 0 13 46 25 25 50 -55 128 42 32 127 11 30 130 30 31 125 1 14
126 23 7 -11 0 0 13 46 55 24 51 -55 127 11 20 125 32 31 129 6 49 123 7 51
124 35 13 -10 0 0 13 47 26 24 52 -55 125 28 28 123 38 41 127 34 1 120 51 39
Uncertainty in time = +/- 9 secs
[Prediction of 2008 Oct 30.0]
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]