|
|
Updated: 2015 JUL 17, 17:24 UT
Event Rank : 89
(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 2015 Aug 12 UT, the 61 km diameter asteroid (921) Jovita will occult a 11.9 mag star in the constellation Aquila for observers along a north-to-south path near New Zealand passing over Auckland
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 13.9 mag (the magnitude of the asteroid) for at most 6.1 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: .
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
161 42 56 -49 0 0 13 54 8 31 329 -55 160 51 57 162 34 25 159 57 24 163 30 35
162 36 20 -48 0 0 13 53 57 31 328 -56 161 45 49 163 27 20 160 51 48 164 23 0
163 30 56 -47 0 0 13 53 45 32 327 -57 162 40 50 164 21 31 161 47 17 165 16 45
164 26 47 -46 0 0 13 53 33 32 326 -57 163 37 3 165 17 2 162 43 53 166 11 54
165 23 57 -45 0 0 13 53 20 33 324 -58 164 34 30 166 13 55 163 41 40 167 8 30
166 22 28 -44 0 0 13 53 8 33 323 -59 165 33 15 167 12 13 164 40 41 168 6 35
167 22 25 -43 0 0 13 52 54 34 321 -59 166 33 22 168 12 1 165 40 59 169 6 15
168 23 52 -42 0 0 13 52 41 34 320 -60 167 34 54 169 13 23 166 42 38 170 7 32
169 26 53 -41 0 0 13 52 27 34 318 -60 168 37 57 170 16 23 167 45 45 171 10 34
170 31 34 -40 0 0 13 52 14 35 317 -61 169 42 37 171 21 9 168 50 23 172 15 25
171 38 2 -39 0 0 13 51 59 35 315 -61 170 48 58 172 27 45 169 56 38 173 22 12
172 46 24 -38 0 0 13 51 45 35 314 -61 171 57 8 173 36 20 171 4 38 174 31 3
173 56 46 -37 0 0 13 51 30 35 312 -61 173 7 14 174 47 1 172 14 28 175 42 7
175 9 20 -36 0 0 13 51 15 35 311 -61 174 19 25 175 59 59 173 26 18 176 55 34
176 24 15 -35 0 0 13 50 59 35 309 -61 175 33 52 177 15 25 174 40 17 178 11 37
Uncertainty in time = +/- 5 secs
Prediction of 2015 Jul 18.0
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]