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The Sun

The Sun is a yellow dwarf star (G2V), about 4.6 billion years old, and the dominant gravitational force in the Solar System. It has a diameter of roughly 1.4 million kilometers and contains around 99.8% of the Solar System’s mass. Nuclear fusion in its core converts hydrogen into helium, producing energy that warms the planets. Above the core lie the radiative and convective zones, followed by the visible photosphere (~5,500 °C), the chromosphere, and the much hotter corona (~2 million °C).

Source: science.nasa.gov

APODs including "The Sun"

Circular Sun Halo

10/06/2021

Circular Sun Halo
Image Credit: Vincenzo Mirabella / NASA APOD

Want to see a ring around the Sun? It's easy to do in daytime skies around the world. Created by randomly oriented ice crystals in thin high cirrus clouds, circular 22 degree halos are visible much more often than rainbows. This one was captured by smart phone photography on May 29 near Rome, Italy. Carefully blocking the Sun, for example with a finger tip, is usually all that it takes to reveal the common bright halo ring. The halo's characteristic angular radius is about equal to the span of your hand, thumb to little finger, at the end of your outstretched arm. Want to see a ring of fire eclipse? That's harder. The spectacular annular phase of today's (June 10) solar eclipse, known as a ring of fire, was briefly visible only when standing along the Moon's narrow shadow track that passes over parts of northern Canada, Greenland, the Arctic, and eastern Russia. The solar eclipse was partial though, when seen from broader regions, including northern Asia, Europe, and parts of the US.