They can be used to classify spirals since it’s a genuine difference between the galaxies. The spiral arms are thought to be density waves. As stars move through a spiral arm, gravitational force modifies the velo... ... middle of paper ... ... than half the stars found in the galaxy are older than four point five billion years old. The Milky Way is as old as the universe itself. There are probably more than one hundred billion galaxies.
Retrieved February 15, 2014, from http://www.burro.astr.cwru.edu/stu This website covers our solar system, stars, extra-solar planets, and theories about the universe. Villanueva, J. C. (2010, March 30). What is a nebula? Universe Today. Retrieved from http://www.universetoday.com/61103/what-is-a-nebula/ What is interstellar medium?
(2013, November 18). How close are we to finding dark matter?. Retrieved from http://www.bbc.co.uk/news/science-environment-24987749http://www.seasky.org/celestial-objects/dark-matter.html Rubin, V. (n.d.). Retrieved from http://www.indiana.edu/~geol105/images/gaia_chapter_1/dark_matter_in_the_universe.htmhttp://www.learner.org/courses/physics/unit/text.html?unit=10&secNum=2 Charles, C. (n.d.). Retrieved from http://www.huffingtonpost.com/2013/12/08/dark-matter-black-holes_n_4408646.htmlhttp://space.about.com/od/deepspace/a/What-Is-Dark-Matter.htm
Also, the distances of the variable stars implied that the globular clusters were far away. (3) He believed that Milky Way was so large that it was the entire Galaxy (4) Spiral Nebulae were just gaseous clouds located within our Milky Way. He modeled this by observing the globular star clusters. (Zabludoff, 2012) Previously, the distance to one of the prominent globular cluster called M13 was determined by an astronomer and from this he assumed that all the globular clusters were nearly the same size. To derive the distance to the star, Shapley used the Cepheids.
Understanding stellar evolution is important to astronomers because it allows them to estimate star age using spectroscopic studies, even though a star might be isolated and not part of a cluster. Star clusters form when an interstellar cloud collapses and fragments. Stars evolve within a cluster with the most massive stars evolving the fastest and creating the heaviest elements in their cores; although lower-mass stars take longer to evolve, they can also create heavy elements. Newly formed elements are scattered into the interstellar medium as the result of supernovae in the case of high-mass stars and in the case of low-mass stars when they shed their envelopes in the form of planetary nebulae. Star formation, evolution, and explosion is a continual process that imbues the interstellar medium with heavy elements and enables the formation of new stars.
The paper focuses on the study revolving around the long gamma ray burst and also the galaxies that form their hosts. The long gamma ray burst have long duration that is more than few seconds and the hypothesis supporting its development states that it develops from the massive stars death. The paper also tries to understand the effect of the gamma ray bursts and how they are related to the redshift distributions in the universe. It tries to analyses the different types of wavelengths that gamma ray burst generates after the collision or merging of bodies in the universe. It explains how recent development in technology has brought man closer in studying gamma ray burst in depth and because of the abilities of the technology, man can understand the different wavelengths generated.
Which suggest that, the universe is expanding because the galaxies are moving away from us. So, if the universe is expanding, then it must have been much smaller in the past. Going back far enough, there was a moment when all the matter in the Universe was packed into a point and expanded outwards and that moment was the big bang. It is possible to work out when the big bang happened by the speed of the galaxies movement from each other about 14 billion years ago. We cannot really see the galaxies moving, but the clue is present in the light coming from them which is known as red
Some scientists theorize that an unknown force, called Dark Energy, may be the cause of this accelerated expansion, while others disagree. For some time, exploding stars, or supernovas, were used as a "cosmic measuring stick" (4). That is, scientists used these supernovas to calculate the age of the universe. In 1998, two groups of astronomers surveyed supernovas in very distant galaxies. These supernovas were much dimmer than expected to be, and calculations proved that the stars were over ten billion light years away, much farther away than they should be had the universe been expanding at a slowing rate, or even a constant rate, as previously theorized (5).
Many people who live on Earth are close minded to what is really out there in the universe. They cannot even begin to fathom the vastness of it and how Earth is just a tiny little speck compared to everything else out there. From the planets to the stars and out towards the edge of the unknown, we can only see what science provides us with. From this, we know that we are nothing but a tiny planet located in a solar system of millions in a galaxy of many more in the universe. A galaxy, also called a nebula, consists of billions of stars, interstellar gas, dust, and dark matter which are all bound to form a massive cloud in which we live in.
Astronomers became certain that the universe began with the Big Bang Theory. The first observation was that it was expanding that means that would separate galaxies and they are becoming lager. The galaxies use to be extremely close together before some kind of explosion which is the big bang theory. Second the big bang theory explains the “Abundance of helium and other nuclei like deuterium in the “Abundance of helium and other nuclei like deuterium in the universe. Third astronomers could not actually see the comic background radiation.