The magnetic field that confines the plasma of a solar coronal filament.

One of the most useful diagnostic tools for the detection of Inclined magnetic fields in solar chromospheric structures is that based on the fact that the Hanle effect in forward scattering at the solar disk center creates linear polarization in some spectral lines, such as those of the He I 1083.0 nm multiplet (Trujillo Bueno et al. 2002; Nature, 415, 403). Here we show how these type of unfamiliar phenomena can be suitably exploited to infer the magnetic field vector of solar coronal filaments from our spectropolarimetric observations with the Tenerife Infrared Polarimeter.