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"
From Moonrise to Sunset
22/11/2008
In this panorama of Earth and sky recorded on Thursday, November 13, the Full Moon rises along the eastern horizon at the far left. Of course, the Full Moon rises at sunset and that Thursday's setting Sun was also captured at the far right. In between, 17 digital images are stitched together to follow the horizon to the south in a lovely twilight portrait of the city of Lisbon, Portugal. The serene view takes in part of the longest bridge in Europe, the Vasco da Gama bridge, beneath the rising Moon and ends at the mouth of the Tagus River looking west toward the sunset and the Atlantic Ocean. The photographer's vantage point was Lisbon's 100 foot high Cristo Rei monument on the south bank of the Tagus, at the foot of the port city's other famous bridge, the Ponte 25 de Abril.