Five decades of solar research at the Mic du Midi Turret-Dome (1960-2010). Part 1: Overview of instrumentation and observations
Résumé
The Pic du Midi Turret-Dome, known as 'Lunette Jean Rösch'or LJR ('lunette' for refractor in French), was scientifically active during five decades between 1960 and 2010. It was dedicated to high spatial resolution observations in solar astronomy. We review fifty years of advances in solar instrumentation and solar physics made by this instrument in various domains, which took advantage of the good seeing at Pic du Midi. First, we summarize some of the LJR results in broad-band and wide-field imagery of the photosphere; as this topic was the initial goal and has been the most important contribution of the refractor, details will be provided in Part 2. Then, we present spectro-polarimetric instrumentation and observations with narrow slit and imaging spectroscopy of the photosphere and the chromosphere. The Turret-Dome also housed an original spectro-coronagraph, and observations of the high temperature coronal plasma are highlighted. Finally, we describe progress in the determination of the solar shape with the heliometer. The LJR remained active until the launch of the Hinode and Solar Dynamics Observatory satellites (in 2006 and 2010, respectively).