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"
The Night Side of Saturn
05/07/1995
July 5, 1995 The Night Side of Saturn Picture Credit: NASA, Jet Propulsion Laboratory,Voyager Project Explanation: This image of Saturn was made in November 1980 by the Voyager 1 spacecraft as it flew past the ringed gas giant planet. From a spectacular vantage point, looking back toward the inner solar system, the robot spacecraft recorded this view of the night side of Saturn casting a sharp shadow across the bright rings. No Earth based telescope could ever take a similar picture. Since Earth is closer to the sun than Saturn, only the day side of the planet is visible from the Earth. For more information see Calvin J. Hamilton's Saturn Page. We keep an archive of Astronomy Pictures of the Day. Astronomy Picture of the Day is brought to you by Robert Nemiroff and Jerry Bonnell . Original material on this page is copyrighted to Robert J. Nemiroff and Jerry T. Bonnell.