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Updated: 2015 JAN 03, 07:24 UT
Event Rank : 98
(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 2015 Feb 03 UT, the 134 km diameter asteroid (81) Terpsichore will occult a 11.7 mag star in the constellation Auriga for observers along a path passing over Halls Creek in Western Australia, and then moving into northern South Australia
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.2 mag to 12.5 mag (the magnitude of the asteroid) for at most 30.8 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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
132 12 38 -24 0 0 15 40 0 8 313 -49 131 13 0 133 13 15 130 33 0 133 55 4
131 12 44 -23 0 0 15 39 54 9 313 -51 130 14 31 132 11 52 129 35 26 132 52 38
130 15 28 -22 0 0 15 39 48 11 314 -52 129 18 33 131 13 15 128 40 18 131 53 3
129 20 39 -21 0 0 15 39 41 12 314 -53 128 24 54 130 17 11 127 47 25 130 56 6
128 28 4 -20 0 0 15 39 33 13 314 -54 127 33 25 129 23 28 126 56 39 130 1 34
127 37 36 -19 0 0 15 39 24 15 315 -55 126 43 57 128 31 56 126 7 51 129 9 18
126 49 5 -18 0 0 15 39 15 16 315 -56 125 56 22 127 42 27 125 20 53 128 19 8
126 2 25 -17 0 0 15 39 5 17 315 -56 125 10 33 126 54 52 124 35 38 127 30 55
125 17 27 -16 0 0 15 38 55 18 315 -57 124 26 24 126 9 5 123 52 0 126 44 32
124 34 7 -15 0 0 15 38 44 20 315 -58 123 43 48 125 24 58 123 9 54 125 59 53
123 52 18 -14 0 0 15 38 32 21 315 -59 123 2 41 124 42 26 122 29 13 125 16 51
123 11 55 -13 0 0 15 38 20 22 316 -60 122 22 56 124 1 23 121 49 54 124 35 20
122 32 54 -12 0 0 15 38 7 23 316 -61 121 44 31 123 21 45 121 11 52 123 55 15
121 55 9 -11 0 0 15 37 54 24 316 -62 121 7 19 122 43 26 120 35 2 123 16 32
121 18 37 -10 0 0 15 37 40 26 316 -62 120 31 18 122 6 22 119 59 22 122 39 5
120 43 15 - 9 0 0 15 37 25 27 316 -63 119 56 24 121 30 30 119 24 47 122 2 52
120 8 57 - 8 0 0 15 37 11 28 316 -64 119 22 34 120 55 45 118 51 14 121 27 48
119 35 43 - 7 0 0 15 36 55 29 316 -65 118 49 44 120 22 5 118 18 40 120 53 50
119 3 27 - 6 0 0 15 36 39 30 315 -65 118 17 51 119 49 26 117 47 2 120 20 54
118 32 8 - 5 0 0 15 36 23 31 315 -66 117 46 53 119 17 45 117 16 18 119 48 58
118 1 43 - 4 0 0 15 36 6 32 315 -67 117 16 47 118 47 0 116 46 25 119 17 59
117 32 9 - 3 0 0 15 35 49 33 315 -67 116 47 31 118 17 7 116 17 20 118 47 54
117 3 24 - 2 0 0 15 35 32 35 315 -68 116 19 2 117 48 5 115 49 2 118 18 40
116 35 26 - 1 0 0 15 35 14 36 315 -68 115 51 18 117 19 52 115 21 28 117 50 15
116 8 12 0 0 0 15 34 56 37 314 -69 115 24 18 116 52 24 114 54 36 117 22 38
Uncertainty in time = +/- 11 secs
Prediction of 2015 Jan 3.0
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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