High resolution solar magnetometry with the spectrograph of the Pic du Midi Turret Dome

We present the flrst results obtained with a new Ferroelectric Liquid Crystal (FLC) polarimeter operating with the spectrograph of the Pic du Midi Turret Dome, since September 2003. We observed the solar granulation around active region NOAA 0459 with the Multichannel Subtractive Double Pass (MSDP) operating mode and analysed the circular polarization of the Na D1 589.6 nm spectral line in terms of longitudinal magnetic flelds in a 2D fleld of view (16 x 142 arc sec). Image quality was fairly good and limited to 0.4 arc sec due to the pixel sampling. This observation reveals the presence of magnetic concentrations of several hundred Gauss which are mainly located in the intergranular lanes. Data analysis performed at two difierent optical depths (line core and line wings) also suggests that magnetic lines are curved and diverge with increasing altitude.

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