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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"

Eiffel Tower Prominence on the Sun

16/02/2022

Video Credit: Hawk Wolinski / NASA APOD

What's that on the Sun? Although it may look like a flowing version of the Eiffel Tower, it is a solar prominence that is actually much bigger -- about the height of Jupiter. The huge prominence emerged about ten days ago, hovered over the Sun's surface for about two days, and then erupted -- throwing a coronal mass ejection (CME) into the Solar System. The featured video, captured from the astrophotographer's backyard in Hendersonville, Tennessee, USA, shows an hour time-lapse played both forwards and backwards. That CME did not impact the Earth, but our Sun had unleashed other recent CMEs that not only triggered Earthly auroras, but puffed out the Earth's atmosphere enough to cause just-launched Starlink satellites to fall back. Activity on the Sun, including sunspots, prominences, CMEs and flares, continues to increase as the Sun evolves away from a deep minimum in its 11-year magnetic cycle. Birthday Surprise: What picture did APOD feature on your birthday? (post 1995)