The Science of Stars
Rochell Clark
August 13, 2012
SCI 151
Robert Austin

Stars are the majority and most widely acknowledged astronomical components that symbolize the most essential development of blocks of galaxies. The age, disbursement, and framework of the night sky in a galaxy maintain a record of the heritage, characteristics, and evolvement of the galaxy. More important, stars are integral to the fabrication and allocation of heavy elements. Notably corresponding to carbon, nitrogen, and oxygen, their functionality is intimately associated with the capabilities of the planetary models, which in turn associate about them. Subsequently, the analysis of the conception, longevity, and perishing of stars is dominant to the subject of astronomy.
Astronomers depend on electromagnetic emissions observed by unique variations of telescopes to calculate the position, structure, conditions, activity, and magnetism of celestial objects. The conduct of the majority of stars indicates they generate a certain measure of energy at each wavelength however additionally carry a pinnacle wavelength and range in which they discharge a significant amount of their remaining stamina. Electromagnetic radiation is transmitted by means of waves at the speed of light (299 792 km/sec) through space. Electromagnetic waves consist of marginal frequency radio waves with the aid of infrared energy and observable luminosity to ultraviolet radiation x-rays as well as high frequency gamma radiation. Alongside one another, a majority of these waves constitute the electromagnetic spectrum. Electromagnetic waves are distinguished by their frequency and wavelength that happen to be inversely affiliated: the more substantial the wave's frequency, the more limited the wavelength (Tools, 2004).
Telescopes render the methods to accumulate and explore, and evaluate electromagnetic radiation from inaccessible realms of the universe. The various models of telescopes are used for uniquely distinguishing aspects of the scale which include visible light, adjacent infrared, microwaves, and consequently radio waves. Planets, stars, gaseous nebulae, and foreign galaxies emerge uniquely at whenever they are observed in every distinctive locale of the spectrum. This is largely due to numerous forms of radiation that are susceptible to alterations in the environment and chemistry of the objects. Additionally considering a subject can be efficiently distinguished by a distinctive wavelength presents the astronomer with fundamental evidence which also includes the applicable temperature. There are varied categories of telescope: optical telescopes collect visible light, but other telescopes such as radio telescopes can collect radiation invisible to the human eye. Since Galileo pioneered the employment of the optical telescope in the 17th century, considerably more potent technology has been engineered, with the inclusion of the Hubble Space Telescope and the new Gemini Telescopes. In 1932, Karl Jansky designed radio telescopes, which have since developed into establishments like the James Clerk Maxwell Telescope (Tools, 2004). The most renowned diagram in astronomy is the Hertzsprung-Russell diagram. This diagram is a plot of luminosity (absolute magnitude) against the coloration of the stars varying from the high-temperature, blue-white stars on the left side of the diagram, to the weak temperature, red stars on the right side (Sparks, 2012). Nearly all of the stars, with the inclusion of the Sun, are determined to be along a region identified as the Main Sequence. Main Sequence stars fluctuate extensively in operative temperature. This translates into the warmer the temperature, the considerably more radiant the star is perceived. Subsequently the main sequence has a tendency to adhere to a band running from the bottom right of the diagram to the top left. These stars are fusing hydrogen to helium in their cores. Stars dedicate the overwhelming majority of their duration as main sequence stars. Other significant organizations of stars located on the H-R diagram are the giants and supergiants; luminous stars that have advanced off the main sequence, and the white dwarfs (Bennett, Donahue, & Schneider, 2010).
Invariably resembling most stars, the life pattern of the Sun originates with an immense cloud of gas and particles comprised predominantly of hydrogen. In the event that the sizable cloud of gas and dust is adequately cold enough, it will steadily contract as a result of the gravitational connection between the debris that makes up the cloud. Ultimately, the persistent contraction will position a considerable amount of burden on the deepest region – the core. Initially, the electrons that were linked with the primarily neutral gases would be stripped off, prompting the gas to develop into charged gas. The positively charged hydrogen nuclei in the core subsequently then collide with one another with such substantial pressure designed to enable them to fuse. This process, recognized as nuclear fusion, swiftly leads to the formation of helium. The energy generated by nuclear fusion inhibits the star from collapsing continued. When it reaches this juncture, the moment nuclear fusion transpires, what was once a haze of gas consequently results in a star. In our situation, the Sun is the after effect. In the over-all existence of the Sun, it is at this point that we now are present. The Sun keeps on burning, i.e., through nuclear fusion. These nuclear responses generate high-energy electromagnetic waves that travel for tens of thousands of years outward. Ultimately, they make contact with the surface and are circulated in to space by means of lower-energy visible, ultraviolet, and infrared light (Villanueva, 2010).
This is precisely what specifically illuminates our planet now. At a later stage, when the hydrogen gets absorbed into helium, there will be no more energy which will enable it to nudge outward and hinder the Sun from collapsing. As a result, it will collapse. The breakdown will position immense heaviness on the helium core and contribute to the helium nuclei there to link into more substantial elements very similar to before. Once again the fusion will push the outer regions outward. In this circumstance, the outward expansion permits the Sun to amplify much larger in comparison to earlier in its lifetime. At this point in the life cycle of the Sun, it will eventually then develops into a Red Giant. Although the external territories continue to grow in size, the helium nuclei in the core will continue to fuse into carbon. At this instant, carbon will no longer additionally fuse further. Consequently the Sun’s core will balance whereas the remaining of its outer provinces will continue with their progression that enables it to ultimately be removed. The core will be known as a white dwarf, while the external regions will be known as a planetary nebula. Conclusively of the life duration of the Sun, the white dwarf will discharge the entirety of its residual heat and will develop into a cold dark mass also known as a black dwarf (Villanueva, 2010). Our Sun is approximately midway through the "main sequence" component of its life span. Throughout this chapter, the Sun burns hydrogen into helium, which yields the heat and light. The Sun appears to have been going through this procedure as long as five billion years. Accordingly, in 13,000 years (15,000 A.D.) it will undergo no tangible change from the energy remaining at the moment. In around five billion additional years, the useable hydrogen (not all the hydrogen) will have been transformed to helium. Consequently the Sun commences burning helium and develops into a red giant. Then the Sun will re-collapse down to a white dwarf and continue for billions of years longer (Bennett, Donahue, & Schneider, 2010).

References
Bennett, J., Donahue, M., & Schneider, N. (2010). The Cosmic Perspective. Stars, Galaxies & Cosmology (6th ed.). Retrieved from The University of Phoenix eBook Collection database.
Sparks, R. (2012). The Hertzsprung-Russell Diagram. Retrieved from http://cas.sdss.org/dr7/en/proj/advanced/hr/
Tools of Astronomers. (2004). Retrieved from http://www.nrccnrc.gc.ca/eng/education/astronomy/topics/tools.html
Villanueva, J. C. (2010). Life Cycle of the Sun. Retrieved from http://www.universetoday.com/56522/life-cycle-of-the-sun/