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Updated: 2020 Aug 29, 02:27 UT
Event Rank : 99
(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 Oct 22 UT, the 187 km diameter asteroid (41) Daphne will occult a 12.2 mag star in the constellation Canis Minor for observers along a path across western West Australia, passing over Exmouth, Kalgoorlie and Esperance.
In the case of an occultation, the combined light of the asteroid and the star will drop by 1.29 mag to 13.09 mag (the magnitude of the asteroid) for at most 16.1 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, 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 TYC 0171-01183-1 by 41 Daphne #1 on 2020 Oct 22
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
123 17 10 -37 0 0 18 10 6.9 34 51 -29 121 16 28 125 13 44 120 29 5 125 57 20 1.41
122 45 15 -36 0 0 18 9 56.6 34 52 -30 120 44 53 124 41 27 119 57 37 125 24 52 1.41
122 11 53 -35 0 0 18 9 46.1 35 53 -31 120 11 42 124 7 49 119 24 29 124 51 8 1.41
121 37 2 -34 0 0 18 9 35.5 35 54 -32 119 36 53 123 32 49 118 49 39 124 16 4 1.41
121 0 39 -33 0 0 18 9 24.7 35 55 -33 119 0 23 122 56 26 118 13 5 123 39 40 1.42
120 22 41 -32 0 0 18 9 13.7 35 57 -34 118 22 10 122 18 37 117 34 43 123 1 52 1.42
119 43 5 -31 0 0 18 9 2.6 35 58 -35 117 42 8 121 39 18 116 54 29 122 22 37 1.42
119 1 47 -30 0 0 18 8 51.3 35 59 -37 117 0 14 120 58 26 116 12 18 121 41 53 1.42
118 18 42 -29 0 0 18 8 39.8 35 60 -38 116 16 22 120 15 57 115 28 4 120 59 36 1.43
117 33 45 -28 0 0 18 8 28.2 35 61 -39 115 30 26 119 31 47 114 41 40 120 15 40 1.43
116 46 51 -27 0 0 18 8 16.4 35 63 -40 114 42 18 118 45 49 113 53 0 119 30 1 1.43
115 57 51 -26 0 0 18 8 4.5 34 64 -41 113 51 50 117 57 59 113 1 52 118 42 34 1.43
115 6 37 -25 0 0 18 7 52.4 34 65 -43 112 58 52 117 8 9 112 8 8 117 53 11 1.44
114 13 0 -24 0 0 18 7 40.2 34 66 -44 112 3 12 116 16 10 111 11 32 117 1 45 1.44
113 16 48 -23 0 0 18 7 27.8 33 68 -45 111 4 35 115 21 54 110 11 50 116 8 7 1.44
112 17 48 -22 0 0 18 7 15.3 33 69 -47 110 2 46 114 25 10 109 8 44 115 12 7 1.45
111 15 44 -21 0 0 18 7 2.6 32 70 -48 108 57 23 113 25 44 108 1 51 114 13 33 1.45
110 10 17 -20 0 0 18 6 49.7 32 71 -50 107 48 1 112 23 22 106 50 41 113 12 12 1.45
109 1 5 -19 0 0 18 6 36.7 31 72 -51 106 34 10 111 17 45 105 34 42 112 7 46 1.46
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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