VUV test of a new polarimeter for spectropolarimetric measurements on board space missions

TL;DR

This paper introduces a new UV-visible spectropolarimeter designed for space missions, detailing its concept, prototypes, and ground testing to evaluate its performance for stellar magnetic field studies.

Contribution

It presents a novel polarimeter concept with temporal modulation for full UV-visible spectropolarimetry, including prototype development and ground performance testing.

Findings

Prototype performance established through ground testing

Polarimeter capable of full UV-visible Stokes measurements

Potential for advanced stellar magnetic field studies

Abstract

High-resolution spectropolarimetry is a useful astronomical technique, in particular to study stellar magnetic fields. It has been extensively used in the past but mostly in the visible range. Space missions equipped with high-resolution spectropolarimeters working in the ultra-violet (UV) are now being studied. We propose a concept of a polarimeter working with temporal modulation and allowing to perform Stokes IQUV measurements over the full UV + Visible range. The purpose of this article is to describe the polarimeter concept, two prototypes and the bench developed to perform on ground testing to establish the performances of this new polarimeter.