
Privacy
Sun | |
---|---|
State | |
Country | |
Capital | |
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.
Calatayud | |
---|---|
State | Aragon |
Country | Spain |
Capital | |
Population | 21717 |
Postcode | 50300 |
Calatayud (Spanish pronunciation: [kalataˈʝuð]; 2014 pop. 20,658) is a municipality in the Province of Zaragoza, within Aragón, Spain, lying on the river Jalón, in the midst of the Sistema Ibérico mountain range. It is the second-largest town in the province after the capital, Zaragoza, and the largest town in Aragón other than the three provincial capitals. It is the seat of the comarca of Calatayud. Its population has been declining during the last decade due to migration.
Gainesville is the name of several places in the United States of America: Gainesville, Alabama...
West Oxfordshire is a local government district in northwest Oxfordshire, England, including...
Tucson (; Spanish: Tucsón; O'odham: Cuk-Ṣon; Navajo: Tó Oostsʼąʼ) is a city in and the county...
Sydney (listen) (SID-nee, Dharug: Cadi) is the capital city of the state of New South Wales, and...