The distance between certain lines in the spectrum reveals the strength of the magnetic field in that location — information that can't be measured directly otherwise. (scientificamerican.com)
A new instrument gave the team minute - by - minute updates on the strengths of magnetic fields in the spots. (sciencemag.org)
When the direction of the magnetic field is altered, then for a specific direction the orientation of the spin density wave also changes abruptly. (sciencedaily.com)