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Updated: 2014 JAN 19, 16:51 UT
Event Rank : 90
(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 Feb 17 UT, the 169 km diameter asteroid (536) Merapi will occult a 11.0 mag star in the constellation Coma Berenices for observers along a path across Western Australia from Eucla to Karratha, Newman and Port Hedland.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.0 mag to 13.9 mag (the magnitude of the asteroid) for at most 12.5 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
136 5 1 -44 0 0 16 54 55 20 5 -29 137 53 25 134 14 17 139 43 57 132 16 21
135 30 44 -43 0 0 16 55 0 21 6 -30 137 18 6 133 41 2 139 7 32 131 44 12
134 55 22 -42 0 0 16 55 5 22 7 -32 136 41 47 133 6 36 138 30 14 131 10 44
134 18 54 -41 0 0 16 55 10 23 7 -33 136 4 30 132 30 58 137 52 4 130 35 56
133 41 21 -40 0 0 16 55 16 24 8 -34 135 26 12 131 54 8 137 12 58 129 59 49
133 2 40 -39 0 0 16 55 22 25 9 -35 134 46 52 131 16 4 136 32 58 129 22 22
132 22 50 -38 0 0 16 55 28 26 9 -36 134 6 30 130 36 45 135 52 1 128 43 33
131 41 51 -37 0 0 16 55 35 27 10 -37 133 25 4 129 56 10 135 10 5 128 3 21
130 59 40 -36 0 0 16 55 41 28 11 -38 132 42 33 129 14 18 134 27 9 127 21 45
130 16 16 -35 0 0 16 55 48 29 12 -39 131 58 53 128 31 5 133 43 12 126 38 41
129 31 36 -34 0 0 16 55 56 29 12 -40 131 14 4 127 46 31 132 58 10 125 54 8
128 45 37 -33 0 0 16 56 3 30 13 -42 130 28 2 127 0 31 132 12 1 125 8 2
127 58 17 -32 0 0 16 56 11 31 14 -43 129 40 45 126 13 3 131 24 44 124 20 20
127 9 31 -31 0 0 16 56 19 32 15 -44 128 52 10 125 24 3 130 36 14 123 30 58
126 19 18 -30 0 0 16 56 28 33 16 -45 128 2 13 124 33 27 129 46 29 122 39 51
125 27 31 -29 0 0 16 56 36 33 17 -46 127 10 50 123 41 9 128 55 24 121 46 54
124 34 6 -28 0 0 16 56 45 34 18 -48 126 17 56 122 47 6 128 2 57 120 52 1
123 38 59 -27 0 0 16 56 55 35 19 -49 125 23 28 121 51 11 127 9 2 119 55 5
122 42 1 -26 0 0 16 57 4 36 21 -50 124 27 19 120 53 16 126 13 34 118 55 57
121 43 8 -25 0 0 16 57 14 36 22 -51 123 29 23 119 53 14 125 16 28 117 54 29
120 42 11 -24 0 0 16 57 24 37 23 -53 122 29 34 118 50 55 124 17 38 116 50 30
119 39 0 -23 0 0 16 57 35 37 24 -54 121 27 42 117 46 11 123 16 57 115 43 48
118 33 25 -22 0 0 16 57 46 38 26 -55 120 23 40 116 38 47 122 14 17 114 34 7
117 25 16 -21 0 0 16 57 57 38 27 -56 119 17 17 115 28 30 121 9 28 113 21 11
116 14 16 -20 0 0 16 58 9 39 29 -57 118 8 22 114 15 3 120 2 21 112 4 39
115 0 11 -19 0 0 16 58 21 39 30 -59 116 56 39 112 58 7 118 52 44 110 44 6
113 42 40 -18 0 0 16 58 34 39 32 -60 115 41 54 111 37 17 117 40 23 109 19 0
112 21 20 -17 0 0 16 58 47 39 34 -61 114 23 47 110 12 3 116 25 3 107 48 43
110 55 43 -16 0 0 16 59 1 39 35 -62 113 1 54 108 41 49 115 6 25 106 12 25
109 25 13 -15 0 0 16 59 15 39 37 -63 111 35 50 107 5 49 113 44 6 104 29 0
Uncertainty in time = +/- 7 secs
Prediction of 2014 Jan 20.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
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