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"
Anticrepuscular Rays Converge Opposite the Sun
24/06/2019
Is there ever anything interesting to see in the direction opposite the Sun? Sometimes there is. Notable items include your own shadow, a shadow of the Moon during a total solar eclipse, a full moon -- in eclipse if the alignment's good enough, a full earth, planets at opposition, glints from planets, the gegenschein from interplanetary dust, the center of a rainbow, hall-of-mountain fogbows, an airplane glory, and something yet again different if your timing, clouds and Sun position are just right. This different effect starts with clouds near the Sun that are causing common crepuscular rays to stream through. In the featured rare image taken from an airplane in mid-April, these beams were caught converging 180 degrees around, on the opposite side of the sky from the Sun, where they are called anticrepuscular rays. Therefore, it may look like something bright is shining at the antisolar point near the image center, but actually it is reverse-shining because, from your direction, light is streaming in, not out.