The proper motion of network bright points and the heating of the solar corona

Abstract

Since it has been proved that acoustic waves are inefficient, it has been widely accepted that the solar corona is heated by waves which propagate along magnetic flux tubes and are generated by the turbulent granular motions. Such motions, however, have not yet been measured nor the involved energy evaluated. We present in this paper the first measurements of the proper motion of the footpoints of magnetic flux tubes, at the photospheric level, outside active regions. For this purpose, we have used a high resolution granulation movie obtained at the Pic du Midi Observatory, in which we were able to identify many network bright points (NBPs)