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"
Pluto at Night
02/10/2025
The night side of Pluto spans this shadowy scene. In the stunning spacebased perspective, the Sun is 4.9 billion kilometers (almost 4.5 light-hours) behind the dim and distant world. It was captured by far flung New Horizons in July of 2015 when the spacecraft was at a range of some 21,000 kilometers from Pluto. That was about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto's tenuous, surprisingly complex layers of hazy atmosphere. Near the top of the frame the crescent twilight landscape includes southern areas of nitrogen ice plains now formally known as Sputnik Planitia and rugged mountains of water-ice in the Norgay Montes.