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Updated: 2014 May 20, 20:18 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 2014 Jul 18 UT, the 37 km diameter asteroid (3939) Huruhata will occult a 10.4 mag star in the constellation Lupus for observers along a large uncertainty path across western West Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 5.8 mag to 16.2 mag (the magnitude of the asteroid) for at most 18.1 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: 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.
Occultation of TYC 7830-03371-1 by 3939 Huruhata on 2014 Jul 18
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
120 4 48 -10 0 0 12 24 49 56 198 -36 120 15 12 119 54 23 121 41 11 118 28 28
119 50 59 -11 0 0 12 24 0 57 198 -36 120 1 26 119 40 33 121 27 41 118 14 21
119 37 5 -12 0 0 12 23 11 58 198 -36 119 47 34 119 26 37 121 14 6 118 0 6
119 23 3 -13 0 0 12 22 20 59 198 -36 119 33 34 119 12 33 121 0 27 117 45 41
119 8 53 -14 0 0 12 21 29 60 198 -35 119 19 26 118 58 19 120 46 41 117 31 4
118 54 31 -15 0 0 12 20 37 61 198 -35 119 5 8 118 43 55 120 32 46 117 16 14
118 39 58 -16 0 0 12 19 45 62 198 -35 118 50 38 118 29 18 120 18 43 117 1 9
118 25 11 -17 0 0 12 18 52 63 198 -35 118 35 54 118 14 27 120 4 28 116 45 48
118 10 8 -18 0 0 12 17 58 64 198 -35 118 20 55 117 59 21 119 50 0 116 30 8
117 54 48 -19 0 0 12 17 4 65 197 -34 118 5 39 117 43 56 119 35 18 116 14 8
117 39 8 -20 0 0 12 16 9 66 197 -34 117 50 4 117 28 12 119 20 19 115 57 46
117 23 8 -21 0 0 12 15 14 67 197 -34 117 34 9 117 12 7 119 5 2 115 40 59
117 6 44 -22 0 0 12 14 18 69 197 -34 117 17 50 116 55 37 118 49 26 115 23 45
116 49 54 -23 0 0 12 13 22 70 197 -33 117 1 6 116 38 42 118 33 26 115 6 3
116 32 36 -24 0 0 12 12 25 71 196 -33 116 43 54 116 21 19 118 17 3 114 47 49
116 14 48 -25 0 0 12 11 28 72 196 -33 116 26 12 116 3 24 118 0 13 114 29 0
115 56 28 -26 0 0 12 10 30 73 196 -33 116 7 58 115 44 56 117 42 53 114 9 35
115 37 31 -27 0 0 12 9 31 74 195 -32 115 49 9 115 25 53 117 25 2 113 49 29
115 17 56 -28 0 0 12 8 32 75 194 -32 115 29 41 115 6 10 117 6 37 113 28 40
114 57 39 -29 0 0 12 7 33 76 194 -31 115 9 32 114 45 44 116 47 34 113 7 5
114 36 36 -30 0 0 12 6 33 77 193 -31 114 48 39 114 24 33 116 27 52 112 44 39
114 14 45 -31 0 0 12 5 32 78 192 -31 114 26 57 114 2 33 116 7 25 112 21 19
113 52 2 -32 0 0 12 4 31 79 190 -30 114 4 24 113 39 39 115 46 11 111 57 1
113 28 21 -33 0 0 12 3 30 80 188 -30 113 40 54 113 15 48 115 24 7 111 31 39
113 3 40 -34 0 0 12 2 28 81 186 -29 113 16 24 112 50 55 115 1 8 111 5 10
112 37 52 -35 0 0 12 1 26 82 183 -29 112 50 48 112 24 56 114 37 9 110 37 27
112 10 54 -36 0 0 12 0 24 83 179 -28 112 24 2 111 57 44 114 12 7 110 8 25
111 42 38 -37 0 0 11 59 20 84 172 -28 111 56 0 111 29 14 113 45 55 109 37 58
Uncertainty in time = +/- 75 secs
Prediction of 2014 May 21.0
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