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"
Sun and Moon and ISS
03/09/2022
On August 25 Sun and Moon could both be seen in planet Earth's daytime skies. And so could the International Space Station. The ISS crossed the disk of the waning crescent Moon as seen from Shunyi district, Beijing, China at about 11:02 am local time. Some 40 kilometers to the southwest, in Fengtai district, the ISS was seen to cross the Sun's disk too. The solar transit was observed only 29 seconds later. Both transits are compared in these panels, composed of processed and stacked video frames from the two locations. The coordinated captures were made with different equipment, but adjusted to show the Sun and Moon at the same scale. The ISS was at a calculated range of 435 kilometers for the lunar transit and 491 kilometers when passing in front of the Sun. Artemis I: Launch Update