Station Maps for the Occultation by (539) Pamina at Saturday, 2009 December 19 (~ 00:24 UT)
(539) Pamina occults a double star!
TDS 3261
Sep 0.9 arcsec PA 182 deg in year 1991
Occultation component A: observable in Portugal, Spain, France and Italy.
Occultation component B: observable in U.K., Belgium, The Netherlands, Germany and Poland.
Component A:
V-Magnitude of target star TYC 1865-01349-1: 10.9 mag
The max duration is expected to be 4.8 sec with a max drop of 2.0 mag.
The event will take place at an altitude of 71 deg and at azimuth 209 deg. The sun will be at an altitude of -71 deg. (At predicted centre line for longitude 0 deg)
Component B:
V-Magnitude of target star TYC 1865-01349-2: 11.3 mag
The max duration is expected to be 4.8 sec with a max drop of 1.7 mag.
The event will take place at an altitude of 59 deg and at azimuth 217 deg. The sun will be at an altitude of -59 deg. (At predicted centre line for longitude E 10 deg)
There is a 1 sigma uncertainty interval of ± 0.67 path widths.
The probabilities to see a positive event:
Centre line: ~ 55 %
Path limits: ~ 43 %
1 sigma lines: ~ 15 %
2 sigma lines: ~ 1 %
(Calculation according to Raymond Dusser, E.A.O.N. Circular #10)
Jean Lecacheux (IMCCE) wrote:
The UCAC instrument is unable to resolve the A and B stars.
So the UCAC2 provides the position and proper motion of a virtual photocentre located “somewhere between A and B”.
At the occultation date this photocentre W from the UCAC2 lies at the position :
05h 37m 30s.11966
+25d 05′ 05″.7532
Steve adopted the following star positions (see his detailed update) :
A component : 05h 37m 30s.1206 +25d 05′ 06″.125
B component : 05h 37m 30s.1183 +25d 05′ 05″.225
… Steve affected to each star a weight proportional to its V luminosity measured by Tycho. That seems all right.
However I my opinion the position uncertainty of the two paths (A on Spain, B on England) may be slightly underestimated in Steve’s update, for the two following reasons.
1/ Nothing warrants us that the A and B stars have a full negligible relative motion in a 19 years interval.
2/ Nothing warrants us that the A and B stars have the same colour.
SO PLEASE OBSERVE OUTSIDE THE 2 SIGMA LINES TOO!
Let other observers know about you observing plans: Announce you station with OccultWatcher !
More information (coordinates, finder charts) at Steve Preston’s prediction:
http://asteroidoccultation.com/2009_12/1219_539_18275.htm
http://asteroidoccultation.com/2009_12/1219_539_18276.htm
Table of potential observing stations and cities with distance from center of predicted path (Derek C. Breit):
http://www.poyntsource.com/New/Google/20091219_18275_Sites.txt
http://www.poyntsource.com/New/Google/20091219_18276_Sites.txt
Map and Coordinates at the web page of E.A.O.N. :
http://astrosurf.com/eaon/Occultations%20December.htm
Good luck with your observation!
Oliver Klös
IOTA-ES
