Solar Research Programs at IRSOL, Switzerland

TL;DR

This paper describes the advanced polarimetric and imaging capabilities of IRSOL's solar research programs, highlighting recent technological enhancements for precise solar magnetic field measurements.

Contribution

It introduces new instrumentation, including a Fabry-Perot filter and adaptive optics, enhancing spectro-polarimetric accuracy and spatial resolution for solar observations.

Findings

Achieved polarimetric precision down to 10^-5

Extended research to monochromatic imaging of the Stokes vector

Improved spatial resolution with adaptive optics

Abstract

The Zurich IMaging POLarimeter (ZIMPOL) developed at ETH Zurich and installed permanently at the Gregory Coude Telescope at Istituto Ricerche Solari Locarno (IRSOL) allows a polarimetric precision down to 10^-5 to be reached. This makes it possible to perform several accurate spectro-polarimetric measurements of scattering polarization and to investigate solar magnetic fields through the signatures of the Hanle and Zeeman effects. The research programs are currently being extended to monochromatic imaging of the Stokes vector with a recently installed Fabry-Perot rapidly tunable filter system with a narrow pass band of about 30mA. The spatial resolution is being improved by the installation of an Adaptive Optics system.