150 years of ground-based solar instrumentation at Meudon observatory (1876-2026)

TL;DR

This paper reviews 150 years of ground-based solar instrumentation development at Meudon observatory, highlighting technological innovations and historical milestones in solar physics research.

Contribution

It provides a comprehensive historical account of ground-based solar instruments developed and used at Meudon from 1876 to 2026, emphasizing pioneering techniques and technological evolution.

Findings

Pioneering role of Meudon in solar instrumentation

Development of innovative observational techniques

Transition from small to large ground-based instruments

Abstract

The Sun has been observed through a telescope for four centuries. However, its study made a prodigious leap at the end of the nineteenth century with the appearance of photography and spectroscopy, then at the beginning of the following century with the invention of the coronagraph and monochromatic filters, and finally in the second half of the twentieth century with the advent of large ground-based telescopes and space exploration. This article retraces the main stages of solar instrumental developments in Meudon, from its foundation by Jules Janssen in 1876 to the present day, limited to ground-based or balloon instrumentation, designed in Meudon and installed there or in other places (Nan{\c c}ay, Pic du Midi, Canary Islands). The Meudon astronomers played a pioneering role in the history of solar physics through the experimentation of innovative techniques. After the golden age of inventions, came the time of large instruments, studied in Meudon but often installed in more favourable sites, and that of space, in a framework of international collaboration, but this is not discussed here.