What forms the suns outer most atmosphere?

The Sun's outermost atmosphere is formed by the corona, which is a plasma composed of extremely hot ionized gases. This layer extends millions of kilometers into space and is visible during a total solar eclipse as a halo. The corona is characterized by its high temperatures, reaching up to several million degrees Celsius, and is believed to be heated by complex magnetic interactions and waves. It is also the source of solar wind, a stream of charged particles that flows outward into the solar system.