Cycle Of Stars

After a time, the hydrogen runs out almost completely, and it collapses. New reactions begin to take place in the core and these reactions cause the star to expand rapidly. As the stars begin to deplete their new fuel, they switch to others. New elements are formed in the cores of stars but they become too heavy. The star has reached its end growth. When it reaches the end, a tremendous amount of energy is released and it begins to shed its outer layers, the gravity is too weak hold onto them anymore. Once the layers are removed, in the stars place is a fiery core called a planetary nebula. Eventually, the core runs out of fuel and it collapses. This star is now in a very dense state, and is called a white dwarf. Eventually, the white dwarf cools until it no longer shines. This dead star is called a brown dwarf.More massive stars, however, have more violent ways of dying. Some stars turn it into a supergiant. Supergiant stars are extremely bright, and are extremely large. Supergiant stars cores, can collapse violently and suddenly. This collapse causes a tremendous explosion, called a

The sun is the main star in the solar system and is the most important source for energy for earth to have life. The suns diameter is 109 times earth and it is has a mass 330,000. 3 quarters of the suns mass is hydrogen, the rest is mostly made up of helium, with much smaller quantities of heavier elements, including oxygen, carbon, neon and iron. The sun is a G-type main-sequence star and it is referred to as a yellow dwarf. It formed approximately 4.567 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. The Sun is the brightest object in the sky, with an apparent magnitude of 26.74. This is 13 billion times brighter than the next brightest star, Sirius, which has an

The sun produces three types of emissions that reach Earth – electromagnetic radiation, solar wind, and neutrinos.

The Low mass stars spend there main life as a fusion machine which turns hydrogen into helium and a very slow and methodical pace. When the energy released by this fusion reaches the surface it is released into space and this is the star luminosity. Over a long, long time sometimes billions of years a low mass star consumes the hydrogen in its core and converts it to helium, at which point the core starts to contract and shrink. Once all of the hydrogen inside the stars core begins to become totally exhausted, the core pressure gives way to the crush of gravity because it has no more fusion occurring in its core at that time. As the core shrinks rapidly and the outer layers start to expand the stars shape begins to grow in size and its luminosity becomes extraordinary brighter due to the outer shell starting to produce fusion more rapidly then the core did during the main sequence life of the star. As this situation grows more rapidly and extreme the core starts to rapidly burn again and fuse its core helium into carbon. Then just before its final death the star ejects its outer layers into space. This leaves only the degenerate carbon core and since this core is still very hot it emits intensely powerful ultraviolet radiation and glows brightly in what is known as a planetary nebula. The nebula fades and cools over around a million or so years and we are left with a white dwarf cooling indefinitely till

Stars, such as our sun begin their life in an entirely different form from the one we come to recognize. Their lives begin in the bitter cold, around 10 degrees Kelvin, which is only a few degrees above the 3 degrees Kelvin temperature of the background of space itself. Their density is also extremely sparse, with a density of around 1 billion particles per cubic metre, which is only a wisp in comparison to the density of around 1410 kilograms per cubic metre that the sun like star will have during its time on the main sequence. Although they may be quite low in density, the clouds are absolutely enormous, spanning up to tens of parsecs (an astronomical unit of measurement that is determined to be around 19 trillion miles) across. In these clouds, there is an abundance of molecular and atomic gases of various types, which will serve as the rough material that will be used to create the stars and solar systems. Hydrogen is the most abundant element found within these clouds, although they can also contain many other trace elements of metals and gasses.

There are seven major spectral types. Stars range from blue and hot to red and cool. The spectral types are: O, B, A, F, G, K, and M (from hottest to coolest). Each of these letters is divided into 10 numerical classes, from hotter to cooler: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. For example, our Sun has the spectral type G2. Spectroscopy is a scientific technique in which the visible light coming from objects (like stars and nebulae) is examined to determine the object's composition, temperature, density, and velocity. The spectrum is the band of colors that white light is composed of, in the order: red, orange, yellow, green, blue, indigo, violet (from long to short wavelength). Newton first discovered that sunlight could be divided into the visible spectrum. The compositions of stars are determined through spectroscopy. Spectroscopy is the study of something using spectra. Recall from the Electromagnetic Radiation chapter that a spectrum is what results when you spread starlight out into its individual

Stars go through phases with each one altering the star. They start as a protostar then ignite to

When we think of stars, we often think that they are all the same. We often think that they are all just big balls of gas burning up to billions of light years away. However, that isn't exactly true. The truth is that stars are very diverse. Just like anything else in our Universe, stars fall into many different classifications based on its defining characteristics. In this essay I will discuss several different types of stars.

The first process every star goes through before its end is the process of their core shrinking. When stars of at least .4 M begin to exhaust their hydrogen supply, the hydrogen starts to fuse in a shell that is outside the helium core. As the shell burns more hydrogen it is also producing more helium, this allows the core to increase in its mass and temperature. When the temperature increases greatly, helium fusion begins to start in what is called a helium flash, causing the star to rapidly decrease in its size and increase its temperature. Once the star has fused all of the helium out of its core, the product of the carbon will fuse which produces a hot core along with the outer shell made up of fusing helium. The more massive a star is,

The works of Ejnar Hertzsprung and Henry Norris Russel have greatly benefited in this regard. To lay out a star on the H-R diagram, all that is required is the star's spectral type and its luminosity.Typical patterns of the H-R diagram show that blue stars are hotter and larger in size, but their life spans are shorter (The reverse is also true). Sometimes they do not follow the pattern sequence leading to what we call supergiants, giants, and white dwarfs. Another way to classify stars is through the luminosity class. Roman numerals are used to identify the

We know of many stars that exist, but the main stars are White dwarfs, Pulsars, Neutron stars, Magnetars, Brown dwarfs, Black Holes, Cepheid Variable stars, Supergiants, Red Giants, Novas, and Quasars. Starting with White Dwarf, this star is usually the size of a planet and is last stage of a stars life, when it loses all its layers from the planetary nebula. This star is very dense and especially hot after it disables its nuclear fuel. It starts to cool done over the next billions of years. Pulsars, this star is practically a white dwarf star, but has electromagic ration beaming out of it. There are two steady lights (electromagic ration) that point in two opposite directions. It always seems to be blinking, but this is just from the motion

If it has a whitish appearance its temperature is somewhere in between like our Sun. We can see how this happens and how we can then divide stars by mass into three main groups (Red Giants, Main Sequence Stars and White Dwarfs [bluish]) on the Hertzsprung-Russell diagram. An HR Diagram is a graph that plots stars as points by measuring their stellar luminosity in typical solar units (x axis) and surface temperature in multiple luminosity of the Sun (y axis). The diagram provides information about stellar radii, because a star’s luminosity depends on both its surface temperature and its surface area or radius. As you can see on the graph stellar radii increase as we go from the high-temperature, low-luminosity corner (lower left)[White Dwarfs] to the low-temperature, high-luminosity corner (upper right) [Red Giants].

All stars are born in nebulae. Nebulae are huge cold clouds of gas and dust. The formation of protostars requires huge clouds of gas and dust collapsing under gravitational forces. The stage of a protostar last an approximate of 50 million years. As stars grow, they also expand. When the core runs out of hydrogen and helium, the contacts and outer layers of the core expand, become cold, and the brightness decreases. This is also known as a Red Giant or a Red Supergiant which mainly consists of the star’s mass. After a while of beginning the process of its death it goes through other stages.

This is the fourth stage of a star’s life cycle. The Star diameter will be about 700,000 km. An average star will live for about 10 billion years in this stage. Our Sun is only about 5 billion years old. After the Infrared becomes a Star, it will continue to burn changing more of its Hydrogen into Helium. Eventually the Hydrogen begins to run out, until the Star becomes a Red Giant.

When elements are heated they emit light at certain wavelengths which we perceive as colors. Spectroscopy analyzes all the wavelengths in a particular beam of light and this information can be used to determine what elements the source of the light contains. So with any object that emits light, we can determine what