To be published in:
The Messenger 96
A procedure for deriving accurate linear polarimetric measurements
H. Lamy1 and
1 Institut d'Astrophysique et de Géophysique - Université de Liège, Avenue de Cointe 5, 4000 Liège, Belgium
* Chercheur Qualifié FNRS, Belgium
We present here a procedure written within the ESO MIDAS
reduction package with the aim of deriving semi-automatically linear
polarization data from CCD images obtained with beam-splitters such
as those available at the ESO 3.6m telescope
equipped with EFOSC2 or at the VLT equipped with FORS1.
This method is adequate for point-like objects and was used for
measuring quasars polarization. We also report on the detection of a
significant image deformation effect, most probably due to the recent
addition to EFOSC2 of a rotatable half-wave plate.