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