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Updated: 2019 Jan 13, 01:01 UT
Event Rank : 70
(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 2019 Feb 09 UT, the 32 km diameter asteroid (727) Nipponia will occult a 9.5 mag star in the constellation Cancer for observers along a somewhat uncertain path across south-western West Australia.
In the case of an occultation, the combined light of the asteroid and the star will drop by 3.51 mag to 12.97 mag (the magnitude of the asteroid) for at most 2.7 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, 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 1395-655-1 by 727 Nipponia on 2019 Feb 9
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 26 51 -37 0 0 14 2 53 32 20 -31 121 48 21 121 5 15 122 17 48 120 35 18 1.27
120 35 11 -36 0 0 14 3 3 33 22 -31 120 56 40 120 13 36 121 26 5 119 43 39 1.27
119 42 7 -35 0 0 14 3 13 34 23 -31 120 3 37 119 20 31 120 33 2 118 50 34 1.27
118 47 37 -34 0 0 14 3 23 34 24 -32 119 9 8 118 25 58 119 38 36 117 55 57 1.27
117 51 34 -33 0 0 14 3 33 35 25 -32 118 13 9 117 29 52 118 42 42 116 59 46 1.27
116 53 55 -32 0 0 14 3 44 36 26 -32 117 15 35 116 32 8 117 45 14 116 1 53 1.27
115 54 34 -31 0 0 14 3 55 36 28 -32 116 16 20 115 32 39 116 46 9 115 2 13 1.27
114 53 23 -30 0 0 14 4 7 37 29 -33 115 15 19 114 31 19 115 45 19 114 0 41 1.27
113 50 17 -29 0 0 14 4 18 37 31 -33 114 12 24 113 28 2 114 42 39 112 57 7 1.26
112 45 7 -28 0 0 14 4 30 37 32 -33 113 7 27 112 22 38 113 37 59 111 51 23 1.26
111 37 43 -27 0 0 14 4 43 38 34 -33 112 0 19 111 14 58 112 31 12 110 43 19 1.26
Uncertainty in time = +/- 3 secs
Prediction of 2019 Jan 13.0
Use these links for further information:
[Planetary Occultations]
[Using the Predictions]
[Observing Details]
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[Reporting Details]
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