An estimate of the magnetic field strength associated with a solar coronal mass ejection from low frequency radio observations

Abstract

We report ground based, low frequency heliograph (80 MHz), spectral (85-35 MHz), and polarimeter (80 and 40 MHz) observations of drifting, non-thermal radio continuum associated with the "halo" coronal mass ejection that occurred in the solar atmosphere on 2013 March 15. The magnetic field strengths (B) near the radio source were estimated to be B ≈ 2.2 ± 0.4 G at 80 MHz and B ≈ 1.4 ± 0.2 G at 40 MHz. The corresponding radial distances (r) are r ≈ 1.9 R ☉ (80 MHz) and r ≈ 2.2 R ☉ (40 MHz).