UV spectropolarimetry opens an entirely new window onto stellar magnetic fields, winds, and activity — never before accessible from space.
Magnetic fields play a fundamental role throughout stellar evolution — from formation in collapsing molecular clouds, through the main sequence, to remnants such as white dwarfs, neutron stars, and magnetars. Yet UV magnetic diagnostics have never been explored from space at high resolution.
Pollux will measure UV circular and linear polarisation across a wide variety of stellar types. Combined with its unprecedented spectral resolution and wavelength range, Pollux will allow the magnetic geometry, wind structure, and chromospheric/coronal activity to be characterised for hundreds of stars per pointing.
Hot Massive Stars
UV resonance lines (C IV, N V, Si IV) are the primary tracers of stellar winds. Polarimetric measurements will constrain wind geometry and magnetic fields of OB stars.
Solar-Type & Cool Stars
Activity cycles, chromospheric emission, and Lyman-α measurements will probe the UV radiation environments of planet-hosting stars.
Stellar Remnants
White dwarfs and hot subdwarfs are bright UV sources. Pollux will constrain their atmospheric compositions, mass-loss, and magnetic fields.
