|
|
Updated: 2015 Jun 12, 16:33 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 2015 Jul 08 UT, the 167 km diameter asteroid (194) Prokne will occult a 9.8 mag star in the constellation Serpens for observers along a path across western West Australia, passing over Geraldton.
In the case of an occultation, the combined light of the asteroid and the star will drop by 2.1 mag to 11.7 mag (the magnitude of the asteroid) for at most 22.2 seconds.
This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: .
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 0927-00081-1 by 194 Prokne on 2015 Jul 8
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
113 13 44 -37 0 0 11 44 37 42 21 -27 112 15 9 114 12 2 112 2 14 114 24 50
113 28 14 -36 0 0 11 44 27 43 21 -27 112 30 27 114 25 44 112 17 43 114 38 21
113 42 10 -35 0 0 11 44 16 44 22 -27 112 45 9 114 38 55 112 32 35 114 51 22
113 55 34 -34 0 0 11 44 5 45 22 -27 112 59 17 114 51 36 112 46 52 115 3 54
114 8 28 -33 0 0 11 43 54 46 22 -27 113 12 53 115 3 49 113 0 37 115 15 58
114 20 53 -32 0 0 11 43 43 47 22 -27 113 25 57 115 15 36 113 13 50 115 27 36
114 32 52 -31 0 0 11 43 32 48 22 -27 113 38 33 115 26 57 113 26 34 115 38 49
114 44 24 -30 0 0 11 43 20 49 22 -27 113 50 40 115 37 54 113 38 49 115 49 39
114 55 31 -29 0 0 11 43 9 50 23 -27 114 2 21 115 48 28 113 50 38 116 0 6
115 6 15 -28 0 0 11 42 57 51 23 -27 114 13 37 115 58 41 114 2 0 116 10 11
115 16 35 -27 0 0 11 42 45 52 23 -27 114 24 28 116 8 31 114 12 58 116 19 56
115 26 34 -26 0 0 11 42 33 53 24 -27 114 34 55 116 18 2 114 23 32 116 29 20
115 36 12 -25 0 0 11 42 21 54 24 -27 114 45 0 116 27 13 114 33 43 116 38 25
115 45 30 -24 0 0 11 42 9 55 24 -26 114 54 44 116 36 6 114 43 32 116 47 12
115 54 29 -23 0 0 11 41 56 56 25 -26 115 4 6 116 44 40 114 53 0 116 55 42
116 3 8 -22 0 0 11 41 43 57 25 -26 115 13 9 116 52 57 115 2 7 117 3 54
116 11 29 -21 0 0 11 41 31 58 26 -26 115 21 52 117 0 57 115 10 55 117 11 49
116 19 33 -20 0 0 11 41 18 59 26 -26 115 30 16 117 8 41 115 19 23 117 19 28
116 27 20 -19 0 0 11 41 5 60 27 -25 115 38 21 117 16 9 115 27 33 117 26 52
116 34 50 -18 0 0 11 40 52 61 28 -25 115 46 9 117 23 21 115 35 25 117 34 0
Uncertainty in time = +/- 2 secs
Prediction of 2015 Jun 12.0
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]