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Updated: 2009 JUL 16, 01:36 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 2009 Aug 19 UT, the 77 km diameter asteroid (61) Danae will occult a 13.2 mag star in the constellation Scorpius for observers along a path centred near Gisborne in New Zealand, with the uncertainty area extending west past Rotorua and Hastings.
In the case of an occultation, the combined light of the asteroid and the star will drop by 0.4 mag to 12.3 mag (the magnitude of the asteroid) for at most 7.7 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
-179 12 0 -42 51 33 11 26 51 51 253 -59 -179 45 35 -43 1 39 -178 38 24 -42 41 13 178 49 57 -43 26 13 -177 13 31 -42 14 14
-179 54 41 -41 50 8 11 27 4 51 252 -60 179 32 13 -42 0 3 -179 21 32 -41 40 1 178 8 57 -42 24 7 -177 57 48 -41 13 32
179 25 15 -40 48 10 11 27 16 51 251 -61 178 52 35 -40 57 55 179 57 57 -40 38 14 177 30 30 -41 21 33 -178 39 25 -40 12 13
178 47 38 -39 45 40 11 27 29 51 250 -61 178 15 25 -39 55 15 179 19 55 -39 35 53 176 54 26 -40 18 29 -179 18 30 -39 10 18
178 12 21 -38 42 38 11 27 41 51 249 -62 177 40 32 -38 52 3 178 44 13 -38 33 0 176 20 37 -39 14 56 -179 55 12 -38 7 48
177 39 16 -37 39 3 11 27 54 51 248 -63 177 7 51 -37 48 21 178 10 45 -37 29 33 175 48 55 -38 10 55 179 30 22 -37 4 42
177 8 15 -36 34 57 11 28 6 51 247 -64 176 37 13 -36 44 8 177 39 22 -36 25 34 175 19 15 -37 6 24 178 58 5 -36 1 1
176 39 14 -35 30 19 11 28 19 51 246 -65 176 8 32 -35 39 24 177 10 0 -35 21 2 174 51 29 -36 1 25 178 27 51 -34 56 45
176 12 5 -34 25 8 11 28 32 51 245 -65 175 41 44 -34 34 8 176 42 32 -34 15 57 174 25 33 -34 55 56 177 59 34 -33 51 54
175 46 45 -33 19 24 11 28 44 50 243 -66 175 16 43 -33 28 19 176 16 53 -33 10 18 174 1 20 -33 49 56 177 33 9 -32 46 26
175 23 9 -32 13 6 11 28 57 50 242 -67 174 53 24 -32 21 57 175 52 59 -32 4 3 173 38 47 -32 43 25 177 8 32 -31 40 21
175 1 12 -31 6 12 11 29 9 50 241 -68 174 31 44 -31 15 1 175 30 45 -30 57 12 173 17 50 -31 36 21 176 45 38 -30 33 37
174 40 51 -29 58 42 11 29 22 50 240 -68 174 11 39 -30 7 28 175 10 9 -29 49 44 172 58 25 -30 28 43 176 24 24 -29 26 15
174 22 3 -28 50 34 11 29 34 49 239 -69 173 53 5 -28 59 18 174 51 7 -28 41 37 172 40 29 -29 20 29 176 4 48 -28 18 11
174 4 46 -27 41 45 11 29 47 49 238 -70 173 36 1 -27 50 29 174 33 36 -27 32 49 172 24 0 -28 11 38 175 46 45 -27 9 25
Uncertainty in time = +/- 10 secs
Prediction of 2009 Jul 16.0
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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