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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"

Venus, Mercury, and the Waning Moon

14/11/2020

Venus, Mercury, and the Waning Moon
Image Credit: Kevin Saragozza / NASA APOD

Yesterday, early morning risers around planet Earth were treated to a waning Moon low in the east as the sky grew bright before dawn. From the Island of Ortigia, Syracuse, Sicily, Italy this simple snapshot found the slender sunlit crescent just before sunrise. Never wandering far from the Sun in Earth's sky, inner planets Venus and Mercury shared the calm seaside view. Also in the frame, right of the line-up of Luna and planets, is bright star Spica, alpha star of the constellation Virgo and one of the 20 brightest stars in Earth's night. Tomorrow the Moon will be New. The dark lunar disk means mostly dark nights for planet Earth in the coming week and a good chance to watch the annual Leonid Meteor Shower.