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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.
Caen | |
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State | Normandy |
Country | France |
Capital | |
Population | 108954 |
Postcode | 14000 |
Caen (, French: [kɑ̃] (listen); Norman: Kaem) is a commune in northwestern France. It is the prefecture of the department of Calvados. The city proper has 108,365 inhabitants (as of 2012), while its urban area has 420,000, making Caen the largest city in former Lower Normandy. It is also the third largest municipality in all of Normandy after Le Havre and Rouen and the third largest city proper in Normandy, also after Rouen and Le Havre. The metropolitan area of Caen, in turn, is the second largest in Normandy after that of Rouen, the 21st largest in France.
It is located 15 kilometres (9.3 miles) inland from the English Channel, 200 kilometres (120 miles) north-west of Paris, and connected to the south of England by the Caen (Ouistreham) to Portsmouth ferry route.