|
|
Updated: 2007 DEC 19, 03:35 UT
Event Rank : 96
(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 Dec 30 UT, the 111 km diameter asteroid (545) Messalina will occult a 11.8 mag star in the constellation Auriga for observers along a broad path across eastern Australia, from Bundaberg across south-eastern Queensland and western New South Wales to Mildura in Victoria and Kingston SE in South Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.5 mag to 14.2 mag (the magnitude of the asteroid) for at most 7.7 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
136 2 21 -40 0 0 12 3 48 10 18 -15 134 43 14 137 23 1 133 39 26 138 30 26
136 52 43 -39 0 0 12 3 45 12 17 -16 135 33 44 138 13 17 134 30 5 139 20 38
137 44 35 -38 0 0 12 3 42 13 16 -17 136 25 39 139 5 9 135 22 4 140 12 33
138 38 2 -37 0 0 12 3 38 14 16 -19 137 19 3 139 58 42 136 15 27 141 6 13
139 33 8 -36 0 0 12 3 34 15 15 -20 138 13 59 140 54 1 137 10 18 142 1 46
140 29 58 -35 0 0 12 3 30 16 14 -21 139 10 34 141 51 11 138 6 42 142 59 16
141 28 39 -34 0 0 12 3 25 17 14 -22 140 8 52 142 50 20 139 4 45 143 58 51
142 29 17 -33 0 0 12 3 20 19 13 -24 141 9 0 143 51 34 140 4 32 145 0 40
143 32 1 -32 0 0 12 3 14 20 12 -25 142 11 5 144 55 2 141 6 10 146 4 50
144 36 59 -31 0 0 12 3 8 21 11 -26 143 15 16 146 0 54 142 9 46 147 11 33
145 44 21 -30 0 0 12 3 1 22 11 -28 144 21 41 147 9 23 143 15 30 148 21 3
146 54 20 -29 0 0 12 2 54 23 10 -29 145 30 32 148 20 40 144 23 32 149 33 32
148 7 9 -28 0 0 12 2 47 24 9 -30 146 42 1 149 35 1 145 34 2 150 49 21
149 23 6 -27 0 0 12 2 38 26 8 -32 147 56 22 150 52 47 146 47 14 152 8 48
150 42 28 -26 0 0 12 2 30 27 7 -33 149 13 53 152 14 18 148 3 23 153 32 20
152 5 40 -25 0 0 12 2 20 28 6 -35 150 34 53 153 40 2 149 22 48 155 0 28
153 33 10 -24 0 0 12 2 10 29 4 -36 151 59 47 155 10 34 150 45 50 156 33 53
155 5 33 -23 0 0 12 1 59 30 3 -38 153 29 5 156 46 35 152 12 56 158 13 23
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]