what makes a star shine?
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A star shines because it is undergoing nuclear fusion (from hydrogen to helium), producing energy (light).
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Our sun is solidly in the average category. The exact average star is about 1,000,000 miles in diameter.\n\nMany other stars are spectacularly larger or smaller.\n\nThe lifespan of larger stars is shorter.  Srars become brighter at the end of their life, when hydrogen nuclei have been exhausted.  \n\nWhen stars become supernovae, other elements are created, the last one being iron, and much material is blown off.\n\nThen you have a dying monarch of light.  Red and white drwarfs.\n\nSites for stellar evolution info:\nhttp://search.yahoo.com/search?fr=ks&p=stellar+evolution\n\nOur sun has a remaining life span at current luminosity of 25 billion years.  That should give us enough time to figure out what to do when it goes into the ending processes.\n\nDetailed information about our sun and neighborhood:\nhttp://www.urantia.org/papers/toc.html\ngo to Paper 41 and Paper 57
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mainly :\nstars generate light, planets only reflect\nplanets move through an orbit (around stars), stars don't
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Yes. Starting from hydrogen, every element is produced inside stars by nuclear fusion. It's a cascade process: light elements join to form heavier elements, all the way down from hydrogen.
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It's mass.  And its not just in star clusters.  Mass is the only major characteristic of stars.  Almost everything else can be derived (temperature, evolutionary track, luminosity) can be determined by their mass.
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Observed from Earth’s surface, stars appear to twinkle because the atmosphere bends light on its way to the ground.  Stars are so far away that they appear as points of light in the sky, so when the atmosphere bends light from a star, it actually prevents the light from the star from reaching our eyes entirely—in other words, the tiny beam of light from the star that could reach our eyes at that point in time gets deflected away from our eyes briefly.  Thus, stars appear to twinkle on and off.  At one instant, a star’s light reaches your eye; at the next instant, it doesn’t.\n\nThe sun is simply too large to twinkle.  Yeah, one beam of light may get scattered away (perhaps to enhance the blueness of our sky), but the beam of light next to it will make it to your eyes, and on average, the whole sun appears nice and bright and untwinkling in the sky.  (Likewise, the moon doesn’t appear to twinkle, either.)\n\nIn space, there’s no atmosphere, no air to change the trajectory of light reaching your eyes (assuming your eyes are safely enclosed in a spacesuit with the rest of you), so the stars will not twinkle.  \n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
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all stars are formed from nebulae (the plural of nebula). Nebula is a term for a cloud of gas, and stars form from gas. Stars more massive than ~ 6 solar masses are expected to supernova, stars less massive than this (like our Sun, of course) become white dwarfs. After a supernova, there may be nothing left, or there could be a remnant: either a neutron star or a blackhole. If the remnant is more massive than around 3 solar masses it will probably end up as a blackhole. Stars are smallest when they are burning hydrogen into helium, which is what stars do during most of their lifetimes. Stars in this stage are sometimes called dwarfs. There are also two other kinds of "dwarfs": white dwarfs are burned-out stars mentioned above (the Learning Center has more info on these), and brown dwarfs are stars which never accumulated enough mass to start burning hydrogen.
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Stars are balls of gas, They burn by converting lighter elements into heavier elements.  The lightest element is hydrogen, but stars make heavier elements as the burn, so really old stars have elements as dense a Iron!\n\nHeres a link to the periodic table:\n\nhttp://www.dayah.com/periodic/\n\nAll the elements between hydrogen and iron could be in a star.\n\nBut the "Easy" answer is to say Hydrogen and Helium!
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Stars spend most of their life fusing hydrogen to helium.  As a star gets near the end of its life it starts to fuse Helium into heavier elements going up to Carbon, Oxygen, Silicon, etc (taking progressively less time to fuse each of them).\n\nEventually the star will have an Iron core but while fusing elements lighter than Iron results in an energy release trying to fuse Iron into something heavier requires energy and so the fusion reaction can not proceed any further.\n\nNow throughout the life a star the star is in a hydrostatic equilibrium between gravity pulling the star together and the radiation pressure from the nuclear fusion pushing the star apart, with the fusion reaction stopping the gravity wins and the star collapses.\n\nThe sudden collapse causes the core to be crushed to very high density at which point protons and electrons combine to form a neutron and a neutrino according to p + e -> n + ν with the neutrino escaping (the neutrinos carry most of the energy).\n\nThe core of the star is now very small and the outer layers fall in and bounce off which is what causes the explosion.\n\nIt takes a couple of hours for the outer layers of the star to actually blow apart (which is what we'd see) so the first evidence that a supernova has occured is the neutrino burst.
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Not a simple question, but  this is two main reasons.\n\n1) Brightness of the Star Play a part.   Assume uniform Atmosphere.\n\n2) The Atmosphere also another part.  Assume stars of the same brightness.\n\n1)  Brightness of the Star Play a part.\nBrighter the Star, less likely the twinkle.   Look at the Moon, does it go Bink Bink?  Too Bright.\n\nBut Dimer stars, under the same Atmospheric conditions, may Bink.\n\n2) The Atmosphere also another part.\nThe Atmosphere is not uniform, look at the sky during the day, sometime, it clear blue,  and other time clouds mass abound.\n\nThe Atmosphere is like a thin soup, with some sliver of bread in it,.  using that example, when the Stars of the same brightness is in the Sky,  imagine when a sliver of bread blocks lightly one of the stars, thus one Bink, and another don't.\n\nIt Real life, Stars are not of the same brightness, and the Atmosphere is not always uniform.  making the issue complex.
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It is not a star but a planet which you can tell since it is not twinkling. Stars are so far away they appear as a point, while planets have a observable disk. Wind in the upper atmosphere then causes the light to bend which causes star light to twinkle but planets do not. \n\nOnce you determine it is a planet because it is not twinkling. You can rule out it being venus since it is too far from the sun. Venus is also usually a bit brighter.\n\nNow it is too bright to be Saturn or certainly any further planet. That leaves Jupiter or Mars. These you can distinguish by color. Mars has a reddish tinge to it. What you are observing does not.\n\n It is Jupiter. If you have a good pair of binoculars you should even be able to make out a couple moons.
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sun has huge amt of hydrogen atom which under the high temp. undergo nuclear fussion reaction to produce helium ion with emission of huge amount of light & heat......so becoz of this light it always shine...& bcoz of that heat the nuclear reaction keep to continue......
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To Answer the First part:\n\nThe life of a star is a continual struggle between the two forces of GRAVITY and NUCLEAR ENERGY. \nThe star’s self gravity or weight tries to compress the star into a smaller sphere of gas. But when a gas is compressed it gets hot, and in the core of a star the gas gets so hot (10 million Kelvins or more) that nuclear reactions occur. In a star like the Sun the nuclear reactions release more energy each second than one billion hydrogen bombs. As this energy works its way out of the star it balances the star’s self-gravity. For most of a star’s life an equilibrium is maintained between self gravity and energy.\n\nPSS Part 2\n\nNot sure what they want here. Since the "young star" is formed from the older star dust, it would have a higher proportion of heavier elements (like Iron and Silicon), since those elements would have been created in the older stars. A new protostar would never have been exposed to these heavier elements, so it would be still Hydrogen and Helium.
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All stars are round, and there are many trillions of stars, although you can only see about 3,000 of them at any one time without a telescope. The sun is a typical star, only much closer than all the others.
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Stars are like the sun, except they are very far away.  Although made from elements that are gases on earth, the stars are not made of gases.  Their gravitational mass compressed the elements to the point of thermonuclear fusion (just like a huge hydrogen bomb).  This fusion reaction give off photons of light (which is why stars shine and the sun “feels” hot).\n\nPlanets are similar to the earth.  Made of different components, some solid, some usually liquid or gaseous.  Planets do not shine of their own light, but reflect the light from the sun.  Planets tend to travel in somewhat fixed orbits around stars.  In addition, some planets have moons circling them.
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Well if you look at the spectrum of a star you'll see a smooth continuum as well as the spectral lines.  Those lines are either absorbtion lines or emission lines of such things as Hydrogen, Helium, Calcium, Iron and a whole heap of others and we know the wavelength of those lines very well so by comparing what we measure them to be with what we have determined in the lab we can calculate how fast the star is moving towards or away us (radial velocity).\n\nThen once we know the radial velocity we just measure where the peak in the continuum is, correct for the radial velocity to find what the wavelength where the emission actually peaks and then since the star is very close to a blackbody we can calculate the temperature (a blackbody of a given temperature will peak at a given wavelength).
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WHY DO STARS TWINKLE?\n\n\nTwinkle, twinkle, little star,\nHow I wonder ...\nThe scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere. \n\nStars (except for the Sun) appear as tiny dots in the sky; as their light travels through the many layers of the Earth's atmosphere, the light of the star is bent (refracted) many times and in random directions (light is bent when it hits a change in density - like a pocket of cold air or hot air). This random refraction results in the star winking out (it looks as though the star moves a bit, and our eye interprets this as twinkling). \n\nStars closer to the horizon appear to twinkle more than stars that are overhead - this is because the light of stars near the horizon has to travel through more air than the light of stars overhead and so is subject to more refraction. Also, planets do not usually twinkle, because they are so close to us; they appear big enough that the twinkling is not noticeable (except when the air is extremely turbulent). \n\nStars would not appear to twinkle if we viewed them from outer space (or from a planet/moon that didn't have an atmosphere).