|
|
Updated: 2011 JAN 07, 16:32 UT
Event Rank : 26
(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 Feb 22 UT, the 24 km diameter asteroid (811) Nauheima will occult a 8.2 mag star in the constellation Gemini for observers along a narrow but quite uncertain path beginning near Grafton and Byron Bay in NSW. The path then moves north-west through Queensland passing near Emerald and Charters Towers.
In the case of an occultation, the combined light of the asteroid and the star will drop by 7.8 mag to 16.0 mag (the magnitude of the asteroid) for at most 16.7 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
166 3 51 -40 3 41 12 46 2 10 311 -40 165 46 29 -40 0 14 166 21 32 -40 7 18 164 19 55 -39 44 16 168 1 9 -40 29 20
160 47 14 -35 57 58 12 47 48 16 313 -43 160 34 39 -35 56 37 160 59 56 -35 59 23 159 30 2 -35 50 16 162 8 34 -36 7 45
157 13 5 -32 45 11 12 49 34 20 315 -45 157 2 16 -32 44 35 157 23 57 -32 45 50 156 6 18 -32 41 52 158 22 10 -32 49 46
154 24 57 -29 58 6 12 51 20 24 316 -47 154 15 7 -29 57 53 154 34 49 -29 58 20 153 24 2 -29 57 8 155 27 25 -29 59 58
152 3 58 -27 27 10 12 53 5 26 317 -49 151 54 46 -27 27 12 152 13 11 -27 27 9 151 6 55 -27 27 41 153 2 11 -27 27 23
150 1 9 -25 7 40 12 54 51 29 317 -50 149 52 25 -25 7 53 150 9 54 -25 7 29 149 6 53 -25 9 13 150 56 22 -25 6 45
148 11 26 -22 56 49 12 56 37 32 317 -51 148 3 3 -22 57 9 148 19 51 -22 56 31 147 19 16 -22 59 7 149 4 24 -22 55 4
146 31 40 -20 52 49 12 58 22 34 317 -52 146 23 33 -20 53 14 146 39 48 -20 52 24 145 41 8 -20 55 40 147 22 53 -20 50 26
144 59 42 -18 54 23 13 0 8 36 317 -53 144 51 48 -18 54 53 145 7 37 -18 53 54 144 10 30 -18 57 41 145 49 31 -18 51 31
143 34 3 -17 0 37 13 1 54 38 317 -54 143 26 20 -17 1 11 143 41 48 -17 0 4 142 45 56 -17 4 17 144 22 44 -16 57 22
142 13 37 -15 10 49 13 3 39 40 317 -54 142 6 2 -15 11 25 142 21 13 -15 10 13 141 26 23 -15 14 46 143 1 21 -15 7 14
140 57 33 -13 24 25 13 5 25 42 317 -55 140 50 6 -13 25 4 141 5 1 -13 23 47 140 11 4 -13 28 38 141 44 30 -13 20 34
139 45 13 -11 41 0 13 7 11 44 316 -56 139 37 52 -11 41 41 139 52 35 -11 40 20 138 59 22 -11 45 25 140 31 30 -11 36 55
138 36 7 -10 0 12 13 8 57 45 316 -56 138 28 51 -10 0 54 138 43 23 - 9 59 29 137 50 47 -10 4 48 139 21 50 - 9 55 55
137 29 48 - 8 21 42 13 10 42 47 315 -56 137 22 36 - 8 22 27 137 37 0 - 8 20 58 136 44 55 - 8 26 28 138 15 4 - 8 17 15
Uncertainty in time = +/- 44 secs
Prediction of 2011 Jan 8.0
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]