|
|
Updated: 2011 AUG 05, 19:10 UT
Event Rank : 51
(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 2011 Dec 21 UT, the 46 km diameter asteroid (219) Thusnelda will occult a 12.7 mag star in the constellation Sextans for observers along a fairly narrow path across Australia from the Gulf of Carpentaria down far western Queensland and across South Australia to Port Lincoln.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.8 mag to 14.3 mag (the magnitude of the asteroid) for at most 11.6 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 Limit1 Path Limit2 Error Limit1 Error Limit2
E. Longitude Latitude U.T. Alt Az Alt
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
139 0 21 - 2 48 44 17 0 31 61 89 -47 139 14 23 - 2 46 48 138 46 18 - 2 50 41 139 49 19 - 2 41 57 138 10 59 - 2 55 30
139 4 3 - 4 4 0 17 1 7 61 87 -46 139 18 5 - 4 2 4 138 49 58 - 4 5 56 139 53 3 - 3 57 12 138 14 38 - 4 10 46
139 6 51 - 5 19 18 17 1 42 61 84 -45 139 20 54 - 5 17 22 138 52 45 - 5 21 15 139 55 55 - 5 12 30 138 17 21 - 5 26 5
139 8 45 - 6 34 42 17 2 18 61 82 -44 139 22 51 - 6 32 45 138 54 38 - 6 36 38 139 57 56 - 6 27 52 138 19 10 - 6 41 29
139 9 48 - 7 50 12 17 2 53 61 80 -43 139 23 56 - 7 48 15 138 55 38 - 7 52 9 139 59 7 - 7 43 22 138 20 4 - 7 57 1
139 9 59 - 9 5 52 17 3 28 61 78 -42 139 24 9 - 9 3 55 138 55 46 - 9 7 49 139 59 28 - 8 59 1 138 20 4 - 9 12 42
139 9 17 -10 21 44 17 4 4 61 75 -41 139 23 32 -10 19 46 138 55 1 -10 23 41 139 58 59 -10 14 51 138 19 10 -10 28 35
139 7 44 -11 37 49 17 4 39 61 73 -40 139 22 3 -11 35 51 138 53 24 -11 39 47 139 57 40 -11 30 55 138 17 23 -11 44 42
139 5 19 -12 54 11 17 5 15 60 71 -40 139 19 42 -12 52 12 138 50 54 -12 56 9 139 55 31 -12 47 14 138 14 41 -13 1 5
139 2 1 -14 10 51 17 5 50 60 69 -39 139 16 30 -14 8 52 138 47 31 -14 12 50 139 52 31 -14 3 53 138 11 4 -14 17 47
138 57 49 -15 27 53 17 6 26 60 67 -38 139 12 24 -15 25 53 138 43 13 -15 29 52 139 48 40 -15 20 52 138 6 31 -15 34 51
138 52 42 -16 45 18 17 7 1 59 65 -37 139 7 23 -16 43 17 138 37 59 -16 47 18 139 43 56 -16 38 16 138 1 1 -16 52 19
138 46 39 -18 3 10 17 7 37 59 63 -36 139 1 27 -18 1 9 138 31 48 -18 5 11 139 38 17 -17 56 5 137 54 31 -18 10 13
138 39 36 -19 21 32 17 8 12 58 61 -35 138 54 33 -19 19 30 138 24 37 -19 23 33 139 31 43 -19 14 24 137 46 59 -19 28 38
138 31 33 -20 40 26 17 8 48 57 59 -34 138 46 38 -20 38 23 138 16 25 -20 42 28 139 24 11 -20 33 15 137 38 24 -20 47 35
138 22 26 -21 59 55 17 9 23 57 57 -33 138 37 41 -21 57 52 138 7 8 -22 1 59 139 15 38 -21 52 41 137 28 42 -22 7 8
138 12 12 -23 20 4 17 9 58 56 56 -32 138 27 38 -23 18 0 137 56 43 -23 22 9 139 6 1 -23 12 47 137 17 49 -23 27 20
138 0 46 -24 40 56 17 10 34 55 54 -31 138 16 24 -24 38 50 137 45 6 -24 43 2 138 55 17 -24 33 35 137 5 41 -24 48 16
137 48 5 -26 2 34 17 11 9 54 53 -30 138 3 56 -26 0 27 137 32 11 -26 4 41 138 43 21 -25 55 9 136 52 14 -26 9 58
137 34 3 -27 25 4 17 11 45 53 51 -29 137 50 8 -27 22 55 137 17 55 -27 27 12 138 30 8 -27 17 34 136 37 21 -27 32 32
137 18 33 -28 48 28 17 12 20 52 50 -27 137 34 54 -28 46 19 137 2 9 -28 50 38 138 15 33 -28 40 53 136 20 55 -28 56 2
137 1 28 -30 12 53 17 12 56 51 49 -26 137 18 6 -30 10 42 136 44 47 -30 15 5 137 59 27 -30 5 13 136 2 48 -30 20 32
136 42 39 -31 38 24 17 13 31 50 48 -25 136 59 36 -31 36 11 136 25 39 -31 40 37 137 41 44 -31 30 38 135 42 52 -31 46 8
136 21 56 -33 5 6 17 14 7 49 47 -24 136 39 14 -33 2 52 136 4 35 -33 7 21 137 22 13 -32 57 14 135 20 54 -33 12 57
135 59 7 -34 33 7 17 14 42 48 46 -23 136 16 48 -34 30 50 135 41 22 -34 35 23 137 0 43 -34 25 8 134 56 42 -34 41 4
135 33 55 -36 2 33 17 15 18 47 45 -22 135 52 2 -36 0 14 135 15 44 -36 4 51 136 37 0 -35 54 27 134 29 58 -36 10 37
135 6 5 -37 33 32 17 15 53 46 44 -21 135 24 40 -37 31 11 134 47 25 -37 35 53 136 10 48 -37 25 18 134 0 25 -37 41 44
134 35 13 -39 6 14 17 16 29 44 44 -20 134 54 20 -39 3 51 134 16 1 -39 8 37 135 41 47 -38 57 51 133 27 39 -39 14 35
Uncertainty in time = +/- 14 secs
Prediction of 2011 Nov 27.0
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]