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
26/05/2019
One of the most spectacular solar sights is an erupting prominence. In 2011, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressively large prominence erupting from the surface. The dramatic explosion was captured in ultraviolet light in the featured time lapse video covering 90 minutes, where a new frame was taken every 24 seconds. The scale of the prominence is huge -- the entire Earth would easily fit under the flowing curtain of hot gas. A solar prominence is channeled and sometimes held above the Sun's surface by the Sun's magnetic field. A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. The energy mechanism that creates a solar prominence is still a topic of research. After our Sun passes the current Solar Minimum, solar activity like eruptive prominences are expected to become more common over the next few years.