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Updated: 2020 Oct 28, 20:15 UT
Event Rank : 100
(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 2020 Dec 06 UT, the 208 km diameter asteroid (13) Egeria will occult a 11.6 mag star in the constellation Auriga for observers along a very wide path across western West Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by only 0.27 mag to 10.18 mag (the magnitude of the asteroid) for at most 18.3 seconds. This event will not be observable visually.
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, in particular 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.
Occultation of UCAC4 660-042510 by 13 Egeria on 2020 Dec 6
Centre Star Star Sun Path Limits Error Limits Alt
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 Crn
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
121 33 31 -37 0 0 15 45 39.7 9 15 -31 124 40 49 118 4 45 125 13 26 117 23 18 2.40
121 18 39 -36 0 0 15 45 44.2 10 15 -32 124 25 2 117 50 50 124 57 29 117 9 32 2.42
121 0 39 -35 0 0 15 45 49.1 11 15 -33 124 6 29 117 33 13 124 38 50 116 51 58 2.43
120 39 30 -34 0 0 15 45 54.6 12 15 -34 123 45 11 117 11 54 124 17 29 116 30 35 2.44
120 15 11 -33 0 0 15 46 0.5 13 16 -35 123 21 7 116 46 52 123 53 26 116 5 19 2.45
119 47 40 -32 0 0 15 46 6.9 14 16 -36 122 54 16 116 18 1 123 26 40 115 36 6 2.46
119 16 51 -31 0 0 15 46 13.8 15 16 -37 122 24 34 115 45 13 122 57 7 115 2 47 2.46
118 42 39 -30 0 0 15 46 21.3 15 17 -37 121 51 58 115 8 17 122 24 44 114 25 9 2.46
118 4 54 -29 0 0 15 46 29.3 16 17 -38 121 16 22 114 26 59 121 49 25 113 42 56 2.47
117 23 25 -28 0 0 15 46 38.0 17 18 -39 120 37 37 113 40 57 121 11 3 112 55 43 2.47
116 37 57 -27 0 0 15 46 47.2 18 19 -40 119 55 34 112 49 45 120 29 30 112 3 2 2.47
115 48 10 -26 0 0 15 46 57.2 18 19 -41 119 10 2 111 52 47 119 44 33 111 4 9 2.47
114 53 40 -25 0 0 15 47 7.9 19 20 -42 118 20 44 110 49 13 118 55 59 109 58 7 2.47
113 53 54 -24 0 0 15 47 19.5 20 21 -43 117 27 21 109 37 54 118 3 29 108 43 32 2.47
112 48 8 -23 0 0 15 47 31.9 20 22 -44 116 29 30 108 17 8 117 6 42 107 18 18 2.47
111 35 25 -22 0 0 15 47 45.4 21 23 -45 115 26 37 106 44 17 116 5 8 105 39 0 2.47
110 14 19 -21 0 0 15 48 0.2 21 24 -45 114 18 4 104 54 47 114 58 11 103 39 17 2.47
108 42 49 -20 0 0 15 48 16.5 22 25 -46 113 2 55 102 39 35 113 45 3 101 4 39 2.47
106 57 36 -19 0 0 15 48 34.8 22 26 -46 111 39 53 99 33 37 112 24 37 96 55 48 2.48
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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