Sun vs Vác

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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.

In its core the Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. This energy, which can take between 10,000 and 170,000 years to escape the core, is the source of the Sun's light and heat. When hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand, eventually transforming the Sun into a red giant. It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, and render Earth uninhabitable – but not for about five billion years. After this, it will shed its outer layers and become a dense type of cooling star known as a white dwarf, and no longer produce energy by fusion, but still glow and give off heat from its previous fusion. The enormous effect of the Sun on Earth has been recognized since prehistoric times. The Sun has been regarded by some cultures as a deity. The synodic rotation of Earth and its orbit around the Sun are the basis of solar calendars, one of which is the predominant calendar in use today.

Source: Wikipedia

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This is a list of auxiliaries of the United States Navy. It covers the various types of ships that support the frontline combat vessels of the United States Navy. Auxiliary ships which function as hospital ships and as oilers are to be found in their own articles: List of United States Navy hospital ships and List of United States Navy oilers. Escort carriers, amphibious warfare vessels, and some mine warfare vessels were also originally classed as auxiliaries but were later given their own hull classification symbols outside the auxiliary series (which all begin with an 'A'). Links to these and other list articles of similar ships can be found throughout this article. Yard and district craft also function as auxiliaries but generally are smaller and less capable than their ocean-going counterparts, and so they generally remain in harbors and coastal areas.

Their hull classification symbols begin with a 'Y'. Ship status is indicated as either currently active [A], ready reserve [R], inactive [I], or precommissioning [P]. Ships in the inactive category include only ships in the inactive reserve, ships which have been disposed from US service have no listed status. Ships in the precommissioning category include ships under construction or on order. Listed ship classes will often state 'MA type' or 'MC type'. The difference is that 'MC Type' refers to ships designed by the United States Maritime Commission aka MarCom, while 'MA Type' refers to ships designed or converted under MarCom's successor agency, the United States Maritime Administration or MarAd. They are in fact the same designs, and the year 1950 is the date at which MarAd succeeded MarCom.

Source: Wikipedia