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Updated: 2008 MAR 31, 03:51 UT
Event Rank : 16
(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 2008 May 04 UT, the 14 km diameter asteroid (1020) Arcadia will occult a 10.1 mag star in the constellation Virgo for observers along a narrow but uncertain path across North Island New Zealand centred from Hastings to Hamilton and slightly west of Auckland. The area of uncertainty extends to large parts of the North Island.
In the case of an occultation, the combined light of the asteroid and the star will drop by 6.2 mag to 16.3 mag (the magnitude of the asteroid) for at most 6.0 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 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
-178 5 24 -48 0 0 6 57 58 34 33 -23 -177 56 1 -178 14 47 -176 35 42 -179 36 15
-178 39 30 -47 0 0 6 58 40 35 34 -23 -178 30 16 -178 48 46 -177 11 2 179 50 53
-179 14 46 -46 0 0 6 59 22 35 35 -23 -179 5 39 -179 23 55 -177 47 27 179 16 46
-179 51 11 -45 0 0 7 0 6 36 36 -22 -179 42 9 179 59 48 -178 24 54 178 41 26
179 31 18 -44 0 0 7 0 50 37 37 -22 179 40 13 179 22 22 -179 3 24 178 4 54
178 52 41 -43 0 0 7 1 35 37 38 -22 179 1 30 178 43 50 -179 42 55 177 27 11
178 12 57 -42 0 0 7 2 21 38 39 -21 178 21 41 178 4 12 179 36 32 176 48 17
177 32 8 -41 0 0 7 3 8 38 40 -21 177 40 48 177 23 28 178 54 57 176 8 14
176 50 15 -40 0 0 7 3 56 39 41 -21 176 58 50 176 41 39 178 12 22 175 27 2
176 7 16 -39 0 0 7 4 44 39 42 -20 176 15 47 175 58 44 177 28 46 174 44 40
175 23 11 -38 0 0 7 5 34 40 43 -20 175 31 39 175 14 43 176 44 7 174 1 9
174 38 1 -37 0 0 7 6 24 40 44 -19 174 46 26 174 29 36 175 58 28 173 16 29
173 51 45 -36 0 0 7 7 15 41 45 -18 174 0 7 173 43 22 175 11 45 172 30 38
173 4 22 -35 0 0 7 8 6 41 47 -18 173 12 42 172 56 2 174 23 59 171 43 37
172 15 51 -34 0 0 7 8 59 41 48 -17 172 24 9 172 7 33 173 35 9 170 55 25
171 26 11 -33 0 0 7 9 52 42 49 -17 171 34 28 171 17 55 172 45 14 170 5 59
170 35 22 -32 0 0 7 10 45 42 50 -16 170 43 37 170 27 6 171 54 12 169 15 20
169 43 20 -31 0 0 7 11 40 42 52 -15 169 51 34 169 35 5 171 2 2 168 23 26
168 50 5 -30 0 0 7 12 35 42 53 -15 168 58 19 168 41 50 170 8 42 167 30 14
167 55 35 -29 0 0 7 13 31 42 55 -14 168 3 48 167 47 20 169 14 11 166 35 43
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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