The Sun is the star that all planets in our Solar System orbit around. It is the large celestial body in our Solar System, the hottest, largest, heaviest, most massive and most gaseous object with the most bodies orbiting it. The Sun's mass equals about 99,864% of the total mass of the entire Solar System. It's mainly made up of hydrogen 73,2% and helium 25,5%. The remaining 1,3% is made up of carbon, oxygen, neon, silicon and iron.
The Sun is however an average or bellow - average sized star. Many stars like UY Scuti, VY Canis Majoris, Betelgeuse, Stephenson 2-18, Antares, etc. completely dwarf the Sun. The Sun is considered large because we can understand the size of it compared to Earth, but can not understand the sizes of these stars compared to the Sun. The Sun is 109,3 times as wide as Earth, like a basketball, compared to a tip of a pin.
The photosphere is outermost layer of the Sun, it is only 500 km thick, which is basically nothing compared to the Sun's radius.Sunspots, which emerge when the mangetic field breaks through the surface, end up here. As well as light, which is created form the energy present.
Solar flares shoot out of the photosphere very violently, bursting ultraviolet, gamma ray, x-ray and radio rays everywhere.All of theses rays of radiation can reach the entire Solar System and are always reaching all the planets, inlcuding Neptune. Remember that the Sun is an average or bellow average sized star, meaning that stars that are more powerful than the Sun are obviously more violent. This phenomenon is called Solar wind, it's continiously blowng materials from the Sun's atmosphere to outer space.
The Sun is cool enough for convection to occur, and it is the main method for heat transfer. Due to this convection, "cells" appear on the visible surface, they're called convective cells. The convective zone reaches depths of around 212,000 km and at depths like those, temperatures reach 200,000 °C. The temperature cools down due to the creation of light at the photosphere.
Basically, the Sun's conventive zone can actually extend from the surface of the Sun, down to even 500,000 km, very deep into the Sun's interior. That's about 70% of the total Solar radius. The Sun's mangetic field is also generated in the Sun's convective zone.
The tachocline lies between the convective exterior and the radiative interior. Both of these rotate at rapidly different speeds, as the convective layer's rotation acts as a liquid, whilst the radiative zone's is exhibited as solid-body rotation.It is hypothesized that a magnetic dynamo within this layer generates the Sun's magnetic field.
Below the tachocline resides the radiative zone. In this zone, the energy generated by nuclear fusion in the core is turned into electromagnetic energy and moves outwards. Here, the temperatures can reach 2 million to 7 million°C. Nuclear fusion emits protons, that are absorbd by other ions. The density drops a hundredfold (from 20 g/cm3 to 0.2 g/cm3) from 0.25 solar radii to the 0.7 radii, the top of the radiative zone.
Most stars have a radiative zone, for the Sun, it engulfs a majority (70%) of our star.
The core of our Sun is where nuclear fusion happens. It is also the hottest part of our Sun, reaching temperatures of 13,600,000 to 15,000,000 °C. Some can say that the temperatures in the core of the Sun reach 27,000,000 to 28,000,000 °C. The core accounts for 25% of the Sun's mass and has a density 20 times that of iron. The core is also 10 times as dense as gold or lead, as it has a density of 150 g/cm3.Other scientists believe the core makes up only 10% of the Sun's mass, while others claim that it actually accounts for 34% of the Sun's mass.
The core of the Sun is indeed extreme. With pressures that reach, well, over 340 billion atmospheres and such high temperatures, the core of the Sun causes more than 600 million tons of hydrogen to be fused into helium, every single second. Every second, the Sun emits much more energy than the entire humanity has ever done since the very beginning, of Adam and Eve / Eva.
Here, hydrogen forms helium and He3 forms helium and hydrogen. The pressures in the core are incredibly extreme. Hydrogen fuses into helium via the proton - proton chain reaction. In small to average sized stars, like our own Sun, this is the main type of nuclear fusion, along with the CNO cycle, although, the CNO cycle is expected to increase as the Sun becomes older. Generally, hydrogen can fuse into helium if 4 atoms of hydrogen make 1 of helium.
The core basically completes all the process of the nuclear fusion, which then releases the energy towards the rest of the interior of the Sun. If the core had a barely larger of smaller rate of fusion, it wouldn't fuse correctly, with a lot of energy released outwards or not enough energy. The Sun's entire lifespan depends on how stable the core is.
The Chromosphere is the lower portion of the Sun's atmosphere. It has a red color and reaches around 4000 kilometers above the surface.The density of the chromosphere decreases with distance from the center of the Sun. Temperatures decrease from the inner boundary at about 6,000 K to a minimum of approximately 3,800 K, before increasing to upwards of 35,000 K at the outer boundary with the transition layer of the corona.
Here, filaments - solar prominiscenes, occur, caused again, by the magnetic field and the relatively cool gases above the photosphere.
The corona is the upper atmosphere, however, even though it is so far away and stretches out thousands of kilometers, its temperature is millions of degrees and the density drops rapidly.
In the corona, the magnetic field affects charged particles to form "lines". They can only be seen, as well as the chromosphere, during an eclipse when the photosphere doesn't obscure the rest of the light of the chromosphere and corona.
The Sun was formed like most stars, through gas collisions and gravity. From the beginning, 4,610,000,000 years ago, large clouds of gasses were pressed together and through gravity clumping them and holding them together and making them spin around the middle, a protostar was formed, also called T Tauri, pre - main sequnce star.
The protostar Sun was only a protostar, it was hydrogen and helium, but not yet ran by fusion, it took 30 - 50 million years to become a normal star. Htdrogen and helium were pressed together. They were orbiting in circles the center and then, thanks to gravity, were pushed towards the center, going all around it, creating a main - sequence star.
What was left of the gas and materials, since there was much, after the very violent and million year lasting formation of the Sun, later turned into planets, the planets we know today: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, as well as pluto and many more thousands of other dwarf planets.
The Sun has played a vital role here on Earth and still plays as we speak. It's hydrogen fuses into helium creating energy, which creates light. This light has allowed life on Earth to begin, evolve and, well, live. Without the Sun, you wouldn't be here reading this page. The Sun won't however always help life on Earth. Eventually, all life will perish. The Sun will eventually die, in 5,39 to 7,72 billion years from now.
The Fate of the Sun and of the entire Solar System, including planet Earth, is very long and tragic. The more hydrogen the Sun burns, the more energy is released and when this energy reaches the surface, the molecules are absorbed by the photosphere, and gradually, more and more are absorbed and radiated into space, causing the Sun to be brighter, and the star become brighter about 10 percent every 1 billion years.
- In 600 million years, Earth's temperature is thought to reach on average, around 70 °C. The increased luminosity will make more water on Earth evaporate, and increase the levels of silicon on the surface causing Co2 in the atmosphere to get lower, and photosynthesis will no longer be possible, causing 99 percent of the plants die in 800 million years.
- In 1.1 billion, the higher luminosity will cause the oceans to evaporate, causing a greenhouse effect that will make Earth's surface a desert. This will go on in 2.3 to 2.8 billion years, the luminosity will cause the temperatures to be 150 °C, even at the poles, causing all life to go extinct. This will go on for 3 - 4 billion years making Earth like Venus is today and even hotter, because of the larger mass and size of Earth, more rocks will be burned on the surface of the planet, causing the temperatures to reach 1.330 °C. The magnetosphere of Earth will have decayed by this time, since the core of Earth will have cooled down, causing radiation of the Sun to enter the atmosphere, making it even hotter at around 1.500 - 2.000 °C, as well as toxic, with active nuclear particles, nuclear waste and toxic nuclear wast with dirt and broken materials, ruining the atmosphere and the surface of Earth. Nothing will be able to survive. Earth will become the worst planet to support life, even worse than Venus and the gas giants, Jupiter, Saturn, Uranus and Neptune. Even the toughest microscopic organisms that can survive very extreme conditions, could not possibly exist on this future planet Earth.
- In 5.39 to 7.72 billion years, the Sun's hydrogen in the core will be completely depleted and the Sun will reach as to what is known the red giant phase of it's evolution. This will begin once all hydrogen is exhausted in the core and the inert helium ash that has built up there becomes unstable and collapses under its own weight. This will cause the core to heat up and get denser, causing the sun to grow in size. The outer layers of the Sun will grow, but the core will get smaller. First, the Sun was thought to reach 300,000,000 km in diameter but latest studies show that it will reach 1,000,000,000 km in diameter. All the planets will be pushed outward but the Sun will become so large that it will definitely devour the planet Mercury, incredibly high, nearly 100% chance to devour Venus and the Sun will likely also devour Earth. Mars was also thought to be devoured, but after research, it's clear that Mars will survive. However, all the planets will get very hot, even Uranus and Neptune. Many moons and dwarf planets will also have liquids, including water, on their surfaces.
- Finally, when all the helium will be depleted, the star will become completely unstable, causing the outer layers to be lost in a planetary nebula. What will remain will be the Sun's core , a white dwarf, with about 45 percent of the previous solar mass, but the size will be around that of Earth, or slightly smaller. After trillion of years, the white dwarf will become cool and dark, a black dwarf. Then the Sun's journey will have ended, never to shine again. By this time, humanity will either cease to exist, OR will be thriving on a distant planet, reading about the Sun, the small star that started it all...........
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