Jean-Henri Focas (Greek: Ιωάννης Ε. Φωκάς; 20 July 1909 – 3 January 1969) was a Greek-French astronomer, painter, designer, illustrator, astrophysicists, photographer, and celestial cartographer who spoke five languages.
He performed visual studies of planetary surfaces from the National Observatory of Athens, Pic du Midi, and Meudon Great Refractor.
When he was in high school he would frequently visit a small astronomical station on Kogevina hill in Corfu built by lunar photographer Félix Chemla Lamèch.
[5][3] While he was at the Pic du Midi he performed a photometric study from 663 negatives that he contributed to collecting himself which he used to determine 7200 different regions of the surfaces of different astronomical phenomena namely planets and moons.
Luckily lunar photographer Félix Chemla Lamèch built a small astronomical station on Kogevina Hill in Corfu.
He wrote papers and continued his complex artistic rendering of different elements in the solar system such as sunspots, variable stars, comets, and mainly the terrain of various planets.
By the early fifties, he continued his research in astrophysics and wrote a paper on the polarized light of the Moon during the total lunar eclipse of January 29–30, 1953, in Athens which was presented by André Danjon to the French Academy of Sciences.
One year later in 1954, he traveled to South France at the Pyrenees Mountains to view astronomical subject matter at the newly built 60 cm telescope of the Pic du Midi Observatory.
When he returned to Athens he introduced new photographic, polarimetric, and micrometric observation methods developed in the French observatories.
[3] By this period Fokas carried out more than a thousand photometric measurements on Jupiter, which formed the basis of his work on the long-term evolution of cloud formations in the upper atmosphere of the planet.
[16] Throughout his life, Focas focused on mastering the use of the equatorial and the meridian telescopes, micrometer, celestial photometry and astro photographic equipment.