A first spectroscopic measurement of the magnetic field strength for an active region of the solar corona

TL;DR

This paper introduces a novel spectroscopic method to directly measure the magnetic field strength in the solar corona using magnetic induced transitions in Fe$^{9+}$, demonstrated with data from HINODE.

Contribution

It presents the first application of magnetic induced transition spectroscopy to determine coronal magnetic field strength.

Findings

Measured the magnetic field strength in a solar active region.

Demonstrated the feasibility of spectroscopic magnetic field measurement.

Provided new data for understanding solar flare origins.

Abstract

For all involved in astronomy, the importance of monitoring and determining astrophysical magnetic field strengths is clear. It is also a well-known fact that the corona magnetic fields play an important part in the origin of solar flares and the variations of space weather. However, after many years of solar corona studies, there is still no direct and continuous way to measure and monitor the solar magnetic field strength. We will here present a scheme which allows such a measurement, based on a careful study of an exotic class of atomic transitions known as magnetic induced transitions in Fe$^{9+}$. In this contribution we present a first application of this methodology and determine a value of the coronal field strength using the spectroscopic data from HINODE.