Helicity and the SOLIS Vector-Spectromagnetograph


SOLIS (Synoptic Optical Long-term Investigations of the Sun) is a suite of three innovative instruments that greatly improve ground- based synoptic solar observations. The main instrument the Vector Spectro-Magnetograph (VSM) is a compact high-throughput vector-polarimeter that measures the magnetic field strength and direction over the full solar disk within 15 minutes. Helicity can be directly calculated from the full-disk vector field data provided by the Stokes inversion of the observed polarized line profiles. We present an anlysis of the difficulties and problems that one faces when interpreting the the helicity derived from VSM data.

Highlights of Astronomy