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"
Moon and Venus over Corona Del Mar Beach
08/03/2004
The crescent Moon passed nearly in front of Venus two weeks ago. The close conjunction of the night sky's two brightest objects created a striking pose for many viewing the evening sky just after sunset. Such a pose, shown above, was captured between clouds over Corona Del Mar Beach in California, USA. To be precise, the Moon appeared to pass only about three degrees from Venus on February 23. A similar conjunction will occur later this month, on March 24, when Venus appears near its furthest from the Sun while the Moon passes only about 2 degrees away.