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"
NGC 2440: Cocoon of a New White Dwarf
24/12/2023
What's that in the center? Like a butterfly, a white dwarf star begins its life by casting off a cocoon of gas that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest cocoon of all. In the featured cocoon, the planetary nebula designated NGC 2440 contains one of the hottest white dwarf stars known. The white dwarf can be seen as the bright orange dot near the image center. Our Sun will eventually become a white dwarf butterfly, but not for another 5 billion years.