|
|
Updated: 2006 APR 19, 23:07 UT
Event Rank : 34
(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 2006 Apr 26 UT, the 58 km diameter asteroid (2906) Caltech will occult a 12.1 mag star in the constellation Ursa Major for observers along a wide uncertainty path across central Western Australia, running from Broome to Albany.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.9 mag to 16.0 mag (the magnitude of the asteroid) for at most 4.7 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Ron Stone, 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
117 30 58 -37 0 0 11 30 22 6 15 -24 117 10 43 117 51 11 115 51 32 119 9 50
117 50 14 -36 0 0 11 30 21 7 15 -25 117 30 16 118 10 10 116 12 11 119 27 45
118 8 56 -35 0 0 11 30 20 8 15 -25 117 49 14 118 28 37 116 32 12 119 45 9
118 27 7 -34 0 0 11 30 19 9 14 -25 118 7 40 118 46 32 116 51 38 120 2 6
118 44 47 -33 0 0 11 30 17 10 14 -26 118 25 35 119 3 58 117 10 30 120 18 37
119 2 0 -32 0 0 11 30 16 11 14 -26 118 43 1 119 20 57 117 28 50 120 34 44
119 18 46 -31 0 0 11 30 14 12 14 -26 119 0 1 119 37 31 117 46 41 120 50 27
119 35 8 -30 0 0 11 30 12 13 14 -26 119 16 35 119 53 40 118 4 3 121 5 49
119 51 6 -29 0 0 11 30 10 14 14 -26 119 32 44 120 9 27 118 20 59 121 20 51
120 6 42 -28 0 0 11 30 7 15 14 -27 119 48 32 120 24 52 118 37 30 121 35 34
120 21 58 -27 0 0 11 30 5 16 14 -27 120 3 58 120 39 57 118 53 37 121 49 58
120 36 54 -26 0 0 11 30 2 17 13 -27 120 19 4 120 54 43 119 9 23 122 4 6
120 51 31 -25 0 0 11 29 59 18 13 -27 120 33 51 121 9 11 119 24 47 122 17 58
121 5 51 -24 0 0 11 29 56 19 13 -27 120 48 20 121 23 22 119 39 51 122 31 34
121 19 55 -23 0 0 11 29 53 20 13 -27 121 2 32 121 37 18 119 54 36 122 44 57
121 33 43 -22 0 0 11 29 50 21 13 -28 121 16 28 121 50 58 120 9 4 122 58 7
121 47 17 -21 0 0 11 29 47 22 13 -28 121 30 9 122 4 24 120 23 15 123 11 4
122 0 37 -20 0 0 11 29 43 23 13 -28 121 43 36 122 17 37 120 37 9 123 23 49
122 13 43 -19 0 0 11 29 40 24 13 -28 121 56 49 122 30 37 120 50 49 123 36 24
122 26 37 -18 0 0 11 29 36 25 13 -28 122 9 50 122 43 25 121 4 14 123 48 48
122 39 20 -17 0 0 11 29 32 26 13 -28 122 22 38 122 56 1 121 17 26 124 1 2
122 51 52 -16 0 0 11 29 28 27 13 -28 122 35 16 123 8 28 121 30 25 124 13 7
123 4 13 -15 0 0 11 29 23 28 13 -28 122 47 42 123 20 44 121 43 12 124 25 4
123 16 25 -14 0 0 11 29 19 29 13 -28 122 59 58 123 32 51 121 55 47 124 36 52
123 28 27 -13 0 0 11 29 15 30 13 -28 123 12 5 123 44 49 122 8 11 124 48 33
123 40 21 -12 0 0 11 29 10 31 13 -28 123 24 3 123 56 38 122 20 24 125 0 7
123 52 6 -11 0 0 11 29 5 32 13 -28 123 35 52 124 8 20 122 32 28 125 11 35
124 3 44 -10 0 0 11 29 0 33 13 -28 123 47 33 124 19 55 122 44 23 125 22 56
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]