|
|
Updated: 2018 JAN 17, 15:45 UT
Event Rank : 85
(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 2018 Feb 14 UT, the 76 km diameter asteroid (1031) Arctica will occult a 11.0 mag star in the constellation Orion for observers along a path passing over Canberra (low altitude). The path then moves north-west through central Australia, before ending near Broome in northern WA.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.51 mag to 14.50 mag (the magnitude of the asteroid) for at most 13.1 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, astrometry for the asteroid kindly provided by Bill Owen, astrometry for the asteroid kindly provided by the IAU Minor Planet Center.
This work has made use of data from the European Space Agency (ESA)mission Gaia (http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, http://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, inparticular the institutions participating in the Gaia Multilateral Agreement.
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 Limit1 Path Limit2 Error Limit1 Error Limit2 Alt
E. Longitude Latitude U.T. Alt Az Alt Crn
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' "
Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude
145 19 9 -34 6 38 15 22 3 19 285 -42 144 38 5 -34 16 2 146 1 22 -33 57 16 143 59 56 -34 25 3 146 42 43 -33 48 24 -0.45
141 41 40 -32 37 16 15 22 28 22 287 -44 141 5 11 -32 46 38 142 18 53 -32 27 56 140 31 6 -32 55 35 142 55 4 -32 19 6 -0.46
138 39 5 -31 10 6 15 22 53 25 288 -46 138 5 34 -31 19 23 139 13 8 -31 0 50 137 34 7 -31 28 16 139 46 5 -30 52 3 -0.46
136 0 39 -29 44 44 15 23 17 27 289 -47 135 29 14 -29 53 57 136 32 30 -29 35 33 134 59 41 -30 2 45 137 3 13 -29 26 50 -0.47
133 40 12 -28 20 56 15 23 42 30 290 -49 133 10 22 -28 30 4 134 10 24 -28 11 50 132 42 15 -28 38 47 134 39 28 -28 3 12 -0.47
131 33 46 -26 58 31 15 24 7 32 290 -50 131 5 10 -27 7 33 132 2 40 -26 49 29 130 38 11 -27 16 11 132 30 28 -26 40 55 -0.47
129 38 37 -25 37 19 15 24 31 34 290 -51 129 11 0 -25 46 16 130 6 28 -25 28 22 128 44 56 -25 54 50 130 33 14 -25 19 52 -0.47
127 52 45 -24 17 13 15 24 56 36 291 -53 127 25 58 -24 26 6 128 19 45 -24 8 21 127 0 40 -24 34 35 128 45 41 -23 59 55 -0.47
126 14 43 -22 58 7 15 25 21 37 291 -54 125 48 37 -23 6 56 126 41 0 -22 49 19 125 23 57 -23 15 20 127 6 13 -22 40 57 -0.47
124 43 21 -21 39 55 15 25 46 39 291 -55 124 17 51 -21 48 40 125 9 1 -21 31 11 123 53 44 -21 57 1 125 33 39 -21 22 53 -0.47
123 17 45 -20 22 33 15 26 10 41 290 -56 122 52 46 -20 31 14 123 42 54 -20 13 53 122 29 7 -20 39 31 124 7 0 -20 5 38 -0.47
121 57 11 -19 5 56 15 26 35 42 290 -57 121 32 39 -19 14 34 122 21 53 -18 57 19 121 9 25 -19 22 47 122 45 32 -18 49 8 -0.47
120 41 4 -17 50 0 15 27 0 44 290 -57 120 16 55 -17 58 35 121 5 21 -17 41 27 119 54 3 -18 6 45 121 28 37 -17 33 18 -0.47
119 28 52 -16 34 42 15 27 24 45 289 -58 119 5 4 -16 43 14 119 52 49 -16 26 11 118 42 31 -16 51 21 120 15 44 -16 18 6 -0.47
118 20 12 -15 19 59 15 27 49 46 289 -59 117 56 42 -15 28 27 118 43 49 -15 11 30 117 34 26 -15 36 32 119 6 26 -15 3 27 -0.48
117 14 41 -14 5 46 15 28 14 48 288 -60 116 51 27 -14 14 13 117 38 2 -13 57 21 116 29 27 -14 22 15 118 0 23 -13 49 20 -0.48
Uncertainty in time = +/- 6 secs
Prediction of 2018 Jan 17.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
[Timing Details]
[Reporting Details]
[Report Form]
[Asteroid Occultation Results]
[Top of Page][Return to Home Page]