PISCO

Outline:

1. Detailed presentation of PISCO

   Click here to see a comprehensive presentation of PISCO.

2. Short presentation of PISCO

PISCO (Pupil Interferometry Speckle COronagraph) is a focal instrument whose purpose is to obtain high angular resolution images using interferometric techniques which permit to circumvent the natural degradation produced by the atmospheric turbulence. Fixed at the focus of a telescope, it allows the acquisition of short exposured images with a large magnification. Chromatic dispersion caused by the atmophere is corrected by  Risley prisms. The elementary images are digitized and processed using bispectral techniques, as developped by André Lannes (formely member of our team). PISCO is now dedicated to the study of binary stars.

PISCO was designed and built at Midi-Pyrénées Observatory (OMP) between 1991 and 1993. All the parts of this project were handled at OMP (designing, mechanics, optics, electronics and control).  This instrument  was used by the astronomical community at Pic du Midi on the Bernard Lyot Telescope (TBL)  until 1998. Due to a change of policy by the time-allocation comittee, it could no longer used at Pic du Midi after 1998. A group of European astronomers involved in the study of binary stars with PISCO decided to look for another host telescope on which PISCO could be mounted and operated on a regular basis. In November 2003, PISCO was successfully installed at the Cassegrain focus of the 1-meter Zeiss telescope of Brera Observatory in Merate (Italy). After a few weeks of tests it became fully operational in January 2004. Subsequent observations confirmed the possibility of observing visual binaries with separations down to 0"14 and with luminosity differences up to 4 magnitudes. Two papers have already resulted from the observations of 2004.

Members of our team: Scardia M. (Italy), Prieur J.-L. (OMP), Koechlin L. (OMP), Aristidi E. (Univ. Nice), Ghigo M. (Italy), Pansecchi L. (Italy), Sala M. (Italy), Argyle R.W. (England), Lampens P. (Belgium), Strigachev A. (Bulgaria), Oblak E. (Besançon), and Kurpinska M. (Poland).

PISCO at the Cassegrain focus of the 1-meter Zeiss telescope of I.N.A.F. -- Brera Astronomical Observatory (Italy) with the ICCD camera of Nice University (France).
 

Some results obtained with PISCO at Pic du Midi

Restored images of multiple stars  2 Cam (left, separations 0"25 and 0"59)  and Beta Del (right, separation 0"22) with bispectral methods from observations of december 1995,  with PISCO and the ICCD detector of Eric Aristidi's team from Nice University.

 Example of data reduction with ADS 11344 (left: long exposure, center: power spectrum, right:  restored image). Angular separations between the 3 components are 0"3 and 0"7. The observations were performed in 1997, with PISCO and the ICCD detector from Nice University.
 

Some results obtained with PISCO in Merate