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A presidio (from the Spanish, presidio, meaning "jail" or "fortification") is a fortified base established by the Spanish in areas under their control or influence.
The term is derived from the Latin word praesidium meaning protection or defense.
In the Mediterranean and the Philippines, the presidios were outposts of Christian defense against Islamic raids. In the Americas, the fortresses were built to protect against pirates and rival colonists, as well as against resistance from Native Americans.
The presidios of Spanish-Philippines in particular, were centers where the martial art of Arnis de Mano was developed, combining Filipino, Latin-American and Spanish fighting techniques.
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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.