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Sun | |
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Population | 0 |
The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy mainly as light and infrared radiation. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometres (864,000 miles), or 109 times that of Earth, and its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System.
Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.The Sun is a G-type main-sequence star (G2V) based on its spectral class. As such, it is informally and not completely accurately referred to as a yellow dwarf (its light is closer to white than yellow). It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process.
Belfast | |
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State | Northern Ireland |
Country | United Kingdom |
Capital | |
Population | 333000 |
Postcode | BT1 5GS |
Belfast ( BEL-fahst; from Irish: Béal Feirste, meaning "mouth of the sand-bank ford", Irish pronunciation: [bʲeːlˠ ˈfʲɛɾˠ(ə)ʃtʲə]) is the capital and largest city of Northern Ireland, standing on the banks of the River Lagan on the east coast. It is the 12th-largest city in the United Kingdom and the second-largest on the island of Ireland. It had a population of 333,871 as of 2015. Belfast suffered greatly in the Troubles: in the 1970s and 1980s it was one of the world's most dangerous cities, with a homicide rate around 31 per 100,000.By the early 19th century, Belfast became a major port. It played an important role in the Industrial Revolution in Ireland, becoming briefly the biggest linen-producer in the world, earning it the nickname "Linenopolis". By the time it was granted city status in 1888, it was a major centre of Irish linen production, tobacco-processing and rope-making.
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