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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"

Cheering a Total Solar Eclipse

15/03/2016

Media Credit: Associated Press, Exploratorium / NASA APOD

What would you do if you saw the Sun disappear? Quite possibly: cheer. That's what many exuberant sky watchers did across Indonesia during a total eclipse of the Sun last week. There and then, the land and sky went dark during the day as our Sun disappeared for a few minutes behind our Moon. Many people watching knew they were witnessing a rare event, and their joyous exclamations can be heard on the featured video. What a far cry this reaction is from centuries ago, when more typical eclipse reactions derived from fear and worry. The video shows first shows a Sun only partly eclipsed by the Moon as totality approached. From many locations, foreground clouds on our Earth either obscured the view or made the view more interesting. The total eclipse was only visible from a narrow swath of Earth that included several Indonesian islands. At the same time, in the opposite direction, NASA's EPIC camera aboard NOAA's DSCOVR satellite captured the shadow of the Moon moving across the Earth. APOD is also available in: Arabic, Bahasa Indonesian, Catalan, Chinese, Chinese, Croatian, Czech, Dutch, Farsi, Farsi, Galego, German, French, Hebrew, Japanese, Korean, Montenegrin, Polish, Romanian, Russian, Serbian, Slovenian, Spanish, and Turkish