Definition of corona

The word "corona" originates from Latin, where it means "crown" or "garland". In the context of astronomy, the term "corona" was first used to describe the visible atmosphere of the Sun, which appears as a ring of light around the Sun's disk during a total solar eclipse. The term was coined in the 17th century by Italian astronomer Giovanni Cassini, who observed the phenomenon during a solar eclipse in 1663. The corona is a layer of hot, ionized gas that extends millions of kilometers into space, surrounding the Sun's surface. In recent years, the term "corona" has taken on a new significance in the context of the COVID-19 pandemic, as medical professionals used the term "coronavirus" to describe the virus that causes the disease. However, this usage is a distinct from the astronomical sense of the word, and is unrelated to the celestial phenomenon.