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Updated: 2008 JAN 07, 03:12 UT
Event Rank : 0
(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 Feb 17 UT, the 82 km diameter asteroid (0) 1998 HO151 will occult a 13.6 mag star in the constellation Virgo for observers along a path beginning over north east New South Wales passing near Coffs Harbour and Lismore. The path moves into Queensland passing near Brisbane, Toowoomba, Gympie and just west of Gladstone and Mackay.
In the case of an occultation, the combined light of the asteroid and the star will drop by 11.1 mag to 24.7 mag (the magnitude of the asteroid) for at most 4.7 seconds.
This update is based on 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
158 49 37 -36 0 0 15 20 57 40 32 -36 159 35 32 158 3 19 160 47 19 156 49 19
158 6 9 -35 0 0 15 21 4 40 33 -37 158 51 52 157 20 3 160 3 19 156 6 20
157 21 47 -34 0 0 15 21 11 41 34 -39 158 7 20 156 35 50 159 18 31 155 22 21
156 36 30 -33 0 0 15 21 18 41 36 -40 157 21 55 155 50 40 158 32 53 154 37 21
155 50 15 -32 0 0 15 21 25 42 37 -41 156 35 35 155 4 29 157 46 23 153 51 16
155 2 59 -31 0 0 15 21 32 42 39 -42 155 48 16 154 17 15 156 58 59 153 4 4
154 14 39 -30 0 0 15 21 40 42 40 -43 154 59 57 153 28 55 156 10 38 152 15 42
153 25 14 -29 0 0 15 21 47 43 41 -45 154 10 33 152 39 27 155 21 16 151 26 6
152 34 39 -28 0 0 15 21 55 43 43 -46 153 20 3 151 48 46 154 30 51 150 35 15
151 42 50 -27 0 0 15 22 3 43 44 -47 152 28 22 150 56 49 153 39 20 149 43 2
150 49 44 -26 0 0 15 22 11 43 46 -48 151 35 26 150 3 31 152 46 38 148 49 24
149 55 16 -25 0 0 15 22 19 44 48 -50 150 41 11 149 8 49 151 52 43 147 54 16
148 59 22 -24 0 0 15 22 27 44 49 -51 149 45 33 148 12 37 150 57 28 146 57 32
148 1 55 -23 0 0 15 22 36 44 51 -52 148 48 27 147 14 49 150 0 50 145 59 6
147 2 51 -22 0 0 15 22 44 44 52 -53 147 49 46 146 15 19 149 2 42 144 58 52
146 2 1 -21 0 0 15 22 53 43 54 -55 146 49 24 145 13 59 148 3 0 143 56 41
144 59 19 -20 0 0 15 23 2 43 56 -56 145 47 13 144 10 42 147 1 36 142 52 24
143 54 35 -19 0 0 15 23 11 43 57 -57 144 43 7 143 5 19 145 58 23 141 45 52
142 47 40 -18 0 0 15 23 20 43 59 -58 143 36 54 141 57 39 144 53 12 140 36 53
141 38 23 -17 0 0 15 23 29 42 61 -60 142 28 26 140 47 30 143 45 54 139 25 13
140 26 31 -16 0 0 15 23 38 42 62 -61 141 17 30 139 34 38 142 36 19 138 10 37
139 11 49 -15 0 0 15 23 47 41 64 -62 140 3 51 138 18 46 141 24 12 136 52 45
137 53 59 -14 0 0 15 23 57 40 65 -63 138 47 15 136 59 37 140 9 21 135 31 16
136 32 39 -13 0 0 15 24 7 40 67 -65 137 27 20 135 36 46 138 51 28 134 5 43
135 7 26 -12 0 0 15 24 16 39 68 -66 136 3 45 134 9 45 137 30 14 132 35 32
133 37 48 -11 0 0 15 24 26 38 70 -67 134 36 2 132 38 1 136 5 13 131 0 3
132 3 6 -10 0 0 15 24 37 37 71 -68 133 3 36 131 0 49 134 35 58 129 18 21
130 22 32 - 9 0 0 15 24 47 36 72 -69 131 25 44 129 17 15 133 1 53 127 29 16
128 35 2 - 8 0 0 15 24 58 34 74 -70 129 41 32 127 26 3 131 22 12 125 31 11
126 39 10 - 7 0 0 15 25 8 33 75 -70 127 49 45 125 25 32 129 35 57 123 21 47
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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