Magnetic configuration of a sunspot region using the H line

Beijing Astronomical Observatory, Chinese Academy of Sciences Beijing 100080, China

Received: 6 June 1995
Accepted: 12 February 1996

Abstract

The configuration of the magnetic field in an active region is analysed using a set of Hβ chromospheric magnetograms and narrow pass-band filtergrams taken at various positions on the line. We found that the chromospheric magnetic field is parallel to the chromospheric features and inhomogeneous. The photospheric magnetic field disappears abruptly in the edge of the penumbra; the chromospheric field extends beyond the penumbral boundary with an inclination of about to the solar surface. Chromospheric superpenumbral filaments show a good correlation with the chromospheric magnetic field and their configurations are related to the photospheric magnetic structures nearby the sunspot. Part of the magnetic flux of the sunspot returns to the neighbouring enhanced networks, which is almost vertical to the solar surface.