A Sun's lifetime, and the activity in each stage?
601849
Early stars are much more active than they are later in life.  After the contraction of the protostellar cloud there is a lot of magnetic field dragged in with it.  This results in a great deal of flare activity, making nearby protostars some of the brightest x-ray sources in the sky! The period of time this takes in the life time of the star depends on its mass; larger stars burn through this part of their lives far faster, and very low mass stars (relative to the sun) still have some pretty impressive flare activity billions of years into their lives. \n\nThe second link discusses the decay rate of X-ray activity (presumably due to flares) in young lower mass stars, and talks about 10 million years as a pretty good number for solar mass stars and hints at 100millions to billions of years for the really low mass ones.  I am sure you can find more information on this elsewhere.\n\nIn the shorter term, our star DOES follow this 11 year sunspot cycle, and probably has longer cycles too that we do not understand.  \n\nThere was a period of 50-100 years called the Maunder minimum 17th or 18th century) where there were almost NO sunspots recorded/ On top of that the Earth became significantly colder, so presumably the solar flux dropped significantly too.  We don't know if that is a cyclic thing, or a random event, but i bet we find out sometime in the next few thousand years.\n\nThe causal relationship between the climate change and the lack of sunspot activity is debatable; it could have been coincidence, or, more likely in my mind, whatever caused the sun to cool down also had the effect of shutting down the solar dynamo that drives the sun's magnetic field.
231076
The sun emits most of its radiation in a wavelength band between 0.1 and 4.0 micrometers (µm). The amount of radiation emitted from a body increases exponentially with a linear rise in temperature.\n \nSee fig 6f-2 in the link below\nhttp://www.physicalgeography.net/fundamentals/6f.html
376592
The sun is in a state of happy equilibrium.\n\nThere are two main forces acting on the sun....gravity and entropy.\n\nThe sun has A LOT of mass.  With all this mass, the sun has a pretty strong gravitational field, so all this mass is pulling on itself and trying to force it to fall toward the center.  In other words, the sun's own weight is trying to collapse it.  The more the sun shrinks and collapses, the more it heats up and the pressure inside increase (as would be expected).\nThe more the sun heats up and the pressure rises, the more it wants to "blow itself apart".  After a certain point, the pressure and heat at the core is high enough for nuclear fusion to take place.  Nuclear fusion releases a lot of energy...so much energy, it is capeable of hold the sun up under its own weight.\n\nAt this point in the sun's life, the forces of gravity trying to pull the sun together and the energy released by nuclear fusion acting to hold the sun up and blow it apart of pretty much balanced.  If one force were to get the upperhand, the other force would work to balance it out.  If the sun were to shrink a little, the rate of nuclear fusion would increase to compensate.  If nuclear fusion increases, the the sun would expand, cool, and nuclear fusion would slow, allowing gravity to pull it back together.\n\nAs the sun runs out of Hydrogen to fuse, the sun will have to fuse heaveier and heavier elements with increaingly less yeild.  In the end however, our sun will expand to become a Red Giant before blowing off a lot of material and become a white dwarf star.
744404
The Sun is the most prominent feature in our solar system. It is the largest object and contains approximately 98% of the total solar system mass. One hundred and nine Earths would be required to fit across the Sun's disk, and its interior could hold over 1.3 million Earths. The Sun's outer visible layer is called the photosphere and has a temperature of 6,000°C (11,000°F). This layer has a mottled appearance due to the turbulent eruptions of energy at the surface. \nSolar energy is created deep within the core of the Sun. It is here that the temperature (15,000,000° C; 27,000,000° F) and pressure (340 billion times Earth's air pressure at sea level) is so intense that nuclear reactions take place. This reaction causes four protons or hydrogen nuclei to fuse together to form one alpha particle or helium nucleus. The alpha particle is about .7 percent less massive than the four protons. The difference in mass is expelled as energy and is carried to the surface of the Sun, through a process known as convection, where it is released as light and heat. Energy generated in the Sun's core takes a million years to reach its surface. Every second 700 million tons of hydrogen are converted into helium ashes. In the process 5 million tons of pure energy is released; therefore, as time goes on the Sun is becoming lighter. \n\n \n\nThe chromosphere is above the photosphere. Solar energy passes through this region on its way out from the center of the Sun. Faculae and flares arise in the chromosphere. Faculae are bright luminous hydrogen clouds which form above regions where sunspots are about to form. Flares are bright filaments of hot gas emerging from sunspot regions. Sunspots are dark depressions on the photosphere with a typical temperature of 4,000°C (7,000°F). \n\nThe corona is the outer part of the Sun's atmosphere. It is in this region that prominences appears. Prominences are immense clouds of glowing gas that erupt from the upper chromosphere. The outer region of the corona stretches far into space and consists of particles traveling slowly away from the Sun. The corona can only be seen during total solar eclipses. (See Solar Eclipse Image). \n\nThe Sun appears to have been active for 4.6 billion years and has enough fuel to go on for another five billion years or so. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. After a billion years as a red giant, it will suddenly collapse into a white dwarf -- the final end product of a star like ours. It may take a trillion years to cool off completely.
754796
sun = constant \nconstant = sun\n\nthe only piece of information you didn't define.
292425
Well, very interesting question I must say. Our Sun was formed about 4600 million years ago and will continue to give out energy for an equal period of time. So, the earth is safe for the next 4600 million years. Phew!!\n\nBut, if you want to know what will be the fate of our sun (or any star for that matter) after it enters the final stages of its life, then read on.....\n\n(1) The first phase will be THE RED-GIANT PHASE. In this phase, the fusion reactions in the core of the sun will stop and it will start shrinking, this will disturb the equilibrium of our sun and it will start expanding like crazy to re-adjust it. Its color will change to red & it will become very very VERY big!\n\n(2) Now, the second stage will be the WHITE DWARF STAGE. Here, the expanding outer shell will be removed eventually and the shrinking Helium core will shrink into an extremely dense ball of matter due to gravitation. The helium nuclei will start to fuse together to form Carbon nuclei & will release tremendous amount of energy in the process & the sun will start glowing white.\n\n(3) Ultimately, the helium fuel will burn out & the sun will fade into space as a dense lump of matter.\n\n\nBut, if we consider the case of a much bigger star (even bigger than our sun), we'll find more final stages. Those stages will be- \na) Supernova- exploding star\nb) Neutron star- After explosion\nc) Pulsar- A spinning neutron star\nd) Black hole- Formed by an indefinite contraction of a heavy neutron star.\n\n:) Hope you enjoyed all the info :)\nHave a nice day
216942
Our sun is indeed a star. As a star,it will go through all the phases that other stars go through like BIG BANG and etc. Yes,our sun will explode one day and that day will be in another million or billion years of time. So,don't worry about it now. Worry about your great grandchildren. Anyway i hope that i had answered your question. Take care.
805940
The people who said it is closer to 4.5 to 5 *billion* years, are correct.\n\nThe sun is a class G star, which has a lifespan of about 10 billion years (the main part of it's lifespan ... after 10 billion years, it expands and goes through a second, larger but shorter-lived phase).  The sun is about 4.5  to 5 billion years old, which means that it's about halfway through its main lifespan.   So it will be here a little bit more than it has been here already ... which is a *very* long time.\n\nIf the earth hasn't been physically destroyed by an asteroid, or some man-made catastrophe we cannot imagine yet, I am quite sure that life will still be going strong on the earth at that time .. but that humans will be long gone.   Either we will have left after making the planet uninhabitable for ourselves, or we will have killed each other off, or we will go extinct through natural causes (like an asteroid that doesn't destroy the planet, but does wipe out most life).  But in all cases, some life forms will survive, and will do quite fine without us.\n\nEven if we blew each other to pieces with nuclear weapons, and wiped out almost all life on the planet due to radiation, some life would survive the radiation (e.g. in the deep oceans) and life would eventually bounce back ... and would begin the process of evolution all over again.  That's what life does.
222779
The Sun sudden bursts of energy contains Gamma rays and X-rays, plus energized particles (protons and electrons). This forms the Solar wind. Flare activity picks up as sunspots increase.\n\nhttp://www.space.com/scienceastronomy/solarsystem/sun-ez.html
776571
Well, I guess I'm sorry I cannot answer your question, but I can tell you my opinion. (We just got done learning this In science class) I think that most of the stars began their very first cycle at the same time, therefor they would be in the same spot right now. Our sun, wich is a MSS will turn into a red giant in about 8 million years.
1054717
The sun is about 4.5 billion years old and about 1/3 rd the way through it's expected life. Scientists have given us a glimpse of what to expect as the sun ages.\n\n1.1 billion years or so, it will become 10% brighter. This will cause the earth to become super heated, all life will be destroyed and the oceans will boil away. Then in another 6.5 billion years, it will double in brightness and burn its supply of hydrogen fuel in its core. The sun will swell and become bigger than what we see today.\n\nAt around 8 billion years or so, the size will increase to 166 times and reach as far as Jupiter. The color will be red and it will be known as a Red Giant, but once the hydrogen fuel is depleted and the sun has reached the outer regions of Jupiter, it will start to shrink, losing both energy and brightness as it quickly consumes it's helium in  in 100 million years or so..\n\nThen, at around 12 billion years, the sun will eject much of its outer layers and become a smoldering, collapsed core that scientists would call a White Dwarf, but this is not the end, for it has one more transformation. It eventually will become a Black Hole.\n\nIf you would like to see what the sun will look like when it becomes a White Dwarf, go to:\nhttp://www.physorg.com/newman/gfx/news/m2_9_large.jpg
460461
A) Galaxy, about 100,000 years.\n\nB) Sun, about 5 seconds\n\nC) Solar System, it depends on if you mean the orbit of Pluto or all the way out to the Oort cloud.
62632
Depends on the mass of the star....but for example for a star with mass similar to the Sun..\n\n1. Protostar contraction for roughly million years or slightly less.\n2. Main-sequence for roughly 9 billion years.  In this stage the core is burning hydrogen to helium.\n3. Giant stage.  Where the core that is filled with helium compresses and starts to heat up and make star expand.\n4. Planetary nebula\n5. White dwarf\n\nSome massive stars will burn other elements like helium and carbon and can turn into neutron stars or black hole.  Black holes happen for stars greater than roughly 25 solar masses.
676858
150 million kms divided by 300000 km/sec\n8 minutes 20 seconds.\n\nHowever... now comes the fun part.\n\nFusion, the energy source of the sun, takes places only in the core. And the sun is so dense, that a photon created down there, takes a lot of time to come out to the surface. It collides, gets absorbed, is re-emitted, takes a day of to dance.\n\nIn all a photon takes a million year or so to surface.\nAnd million years plus 8 minutes to arrive at the earth.
938268
The process of making food in a plant from the sun's energy
540756
check out this site for general information\nwww.nineplanets.org/sol.html \n\nhttp://sohowww.nascom.nasa.gov/\n\nhttp://www.spaceweather.com/\n\n\nthese are just some sites. is there anything in particular that you would like to know about the sun??
156733
Sun has a nuclear reaction (fission of Hydrogen gas)to radiate energy. Theoratically as much as Hydrogen is being used in the process of energy production the net quantity of hydrogen is being reduced and so net amount of reacting atoms is decreasing. Thus energy of sun is being reduced. However, the rate of decrease in the active mass is so slow that it can not be measured in course of few centuries.\n\nThe much referred worming of air or global worming, as replied here by one other, is due to increasing pollution of air or green effect.