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"
A Super Lunar Corona
12/11/2025
What are those colorful rings around the Moon? A corona. Rings like this will sometimes appear when the Moon is seen through thin clouds. The effect is created by the diffraction of light around individual, similarly-sized water droplets in an intervening but mostly transparent cloud. Since light of different colors has different wavelengths, each color diffracts differently. Lunar coronae are one of the few color diffraction effects that can be easily seen with the unaided eye. The featured image of a lunar corona was captured around last week's full Super Moon from near Knight's Ferry, California, USA. To the right of the full Moon is the giant orange star Botein. Similar coronae that form around the Sun are typically harder to see because of the Sun's great brightness.