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Updated: 2007 JUL 09, 20:26 UT
Event Rank : 93
(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 Aug 04 UT, the 158 km diameter asteroid (804) Hispania will occult a 11.9 mag star in the constellation Scorpius for observers along a path beginning in South Australia west of Ceduna. The path move north and into Western Australia passing over Halls Creek and just west of Wyndam.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.8 mag to 12.0 mag (the magnitude of the asteroid) for at most 20.4 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
125 20 38 -10 0 0 12 3 51 56 171 -36 126 5 32 124 35 48 126 47 48 123 53 43
125 36 52 -11 0 0 12 3 38 57 171 -36 126 21 56 124 51 53 127 4 22 124 9 38
125 53 17 -12 0 0 12 3 26 58 171 -37 126 38 32 125 8 7 127 21 9 124 25 43
126 9 54 -13 0 0 12 3 14 59 171 -37 126 55 20 125 24 32 127 38 8 124 41 57
126 26 42 -14 0 0 12 3 1 60 171 -38 127 12 21 125 41 7 127 55 20 124 58 21
126 43 42 -15 0 0 12 2 48 61 171 -38 127 29 35 125 57 54 128 12 47 125 14 55
127 0 55 -16 0 0 12 2 36 62 172 -39 127 47 2 126 14 52 128 30 29 125 31 40
127 18 21 -17 0 0 12 2 23 63 172 -39 128 4 45 126 32 3 128 48 27 125 48 36
127 36 2 -18 0 0 12 2 9 64 172 -39 128 22 42 126 49 27 129 6 40 126 5 45
127 53 58 -19 0 0 12 1 56 65 172 -40 128 40 56 127 7 5 129 25 11 126 23 7
128 12 9 -20 0 0 12 1 43 66 172 -40 128 59 27 127 24 58 129 44 0 126 40 41
128 30 37 -21 0 0 12 1 29 67 172 -40 129 18 15 127 43 6 130 3 7 126 58 31
128 49 22 -22 0 0 12 1 16 68 172 -41 129 37 21 128 1 29 130 22 34 127 16 35
129 8 25 -23 0 0 12 1 2 69 172 -41 129 56 47 128 20 10 130 42 22 127 34 54
129 27 47 -24 0 0 12 0 48 70 173 -41 130 16 33 128 39 9 131 2 31 127 53 31
129 47 30 -25 0 0 12 0 34 71 173 -41 130 36 41 128 58 26 131 23 3 128 12 24
130 7 33 -26 0 0 12 0 20 72 173 -42 130 57 11 129 18 2 131 43 59 128 31 37
130 27 59 -27 0 0 12 0 6 73 173 -42 131 18 5 129 38 0 132 5 20 128 51 8
130 48 47 -28 0 0 11 59 52 74 174 -42 131 39 24 129 58 19 132 27 7 129 11 0
131 10 1 -29 0 0 11 59 38 75 174 -42 132 1 9 130 19 1 132 49 22 129 31 13
131 31 40 -30 0 0 11 59 23 76 175 -43 132 23 22 130 40 8 133 12 6 129 51 49
131 53 47 -31 0 0 11 59 9 77 175 -43 132 46 4 131 1 40 133 35 21 130 12 49
132 16 23 -32 0 0 11 58 55 78 176 -43 133 9 16 131 23 39 133 59 9 130 34 15
132 39 29 -33 0 0 11 58 40 79 177 -43 133 33 1 131 46 7 134 23 31 130 56 7
133 3 7 -34 0 0 11 58 25 80 178 -43 133 57 20 132 9 5 134 48 30 131 18 27
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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