Measurement of the evolution of the magnetic field of the quiet photosphere during a solar cycle

2017/08/10 by R. Ramelli, M. Bianda, Ramelli, Renzo +7
Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies

paper · pdf · doi:10.48550/arxiv.1708.03287

openalex publication_date 2017/08/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

The solar photosphere is filled by a magnetic field which is tangled on scales much smaller than the resolution capability of solar telescopes. This hidden magnetic field can be investigated via the Hanle effect. In 2007 we started a synoptic program to explore if the magnetic flux of the quiet photosphere varies with the solar cycle. For this purpose we applied a differential Hanle effect technique based on observations of scattering polarization in C₂ molecular lines around 514.0 nm, taken generally every month. Our results now span almost one complete solar cycle.

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