There’s much more to the Sun than the brilliant ball we see in the sky. Eruptions on the surface produce towers of hot gas, and a million-degree outer atmosphere extends far into space. Those structures are impossible to see in the glare of the solar disk, which is a million times brighter. But an astronomer born 125 years ago today invented a device to block out the disk, revealing the extended Sun.

Bernard Lyot was born in Paris. He trained as an engineer, then taught at a Paris high school. While there, he became interested in astronomy, and even built his own telescopes.

In 1920, he joined France’s Meudon Observatory. He worked there until his death, during an eclipse expedition, in 1952. He was especially interested in the Sun, and in developing new tools for studying it.

In the 1930s, he perfected the coronagraph. It uses a series of lenses and filters to block out the Sun. That reveals the eruptions, known as prominences, and the outer atmosphere — the corona. Before then, these features were visible only during solar eclipses.

Lyot used his invention to snap the first pictures of the prominences and corona not taken during an eclipse. And at a conference in 1938, he wowed his fellow astronomers with movies of those features.

Today, astronomers around the world use the invention to keep a close eye on the space near the Sun.

A spacecraft is flying into that region, and we’ll have more about that tomorrow.
 

Script by Damond Benningfield