Discovery of the Expansion of the Universe

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.

Have you ever looked up into the sky on a clear night and wondered how the stars and galaxies came to be? This paper will tell you about those small pinpricks of light in the sky. It will explain the great discoveries that astronomers like Galileo, Newton, and Hubble made. This paper will tell you everything about the stars and galaxies. A galaxy is a system of millions or billions, maybe even trillions of stars that are composed with gas and dust, which is held together by gravitational attraction.

This occurs when a massive galaxy swallows up stars from the smaller satellite galaxies that orbit it (Bennett et al. 630). Through galactic cannibal... ... middle of paper ... ... is very difficult for astronomers to predict events with absolute certainty; astronomers can only create probable simulations of different scenarios that could occur. While the exact details are still not known with certainty, the collision between Andromeda and the Milky Way will happen and the spiral galaxy we know and live in will transform into the giant elliptical, Milkomeda. Works Cited Bennett, James O’, et al.

Astronomers believe that shock waves passing through interstellar matter initiates star formation, which happens when gravity starts... ... middle of paper ... ...Works Cited Brown dwarfs. (n.d.). Retrieved February 15, 2014, from http://www.coolcosmos.ipac.caltech.edu This is an educational and outreach website for infrared astronomy and related topics. Cain, F. (2009, January 28). Types of stars.

The stars are enormous heavenly bodies that are luminous, and their components are held tightly together by gravity. The stars are often grouped together in constellations; these were the stars that were readily visible by the earliest stargazers, and were not blocked by the various heavenly bodies. Supernovas are stars that have exploded in a violent fashion, thus changing their shape and brightness in the night sky, and forever leaving their scar in the universe. There are a number of stars in the universe whose count is infinite and no one can configure the exact amount. Stars in the universe vary from each other by existence in constellations such as Orion, the plough, the great south and Leo among many others.

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. Although it cannot be very well explained, dark matter makes up at least 90% of a galaxy’s mass. Galaxies also contain billions upon billions of stars and their diameter can range from 1,500 to 300,000 light years. That’s huge! The Milky Way, the galaxy in which we live in, is one of about 170 billion galaxies in the observable universe.

‘There are more stars than all of the grains of sand on earth.’(Star Facts, 2005:1) Looking up at the sky on a vibrant night, the vision is naturally lit one with millions of vivacious, glistening stars. The tenacity of this essay is to explore the lifecycle of a star, thence, signify its manifestation in the universe. A fundamental part of our universe is stars. Hence, these miniature luminous forms are essentially very immense in magnitude and it is merely due to their substantial distance from Earth that they appear so trivial. Scientifically, a star is a ball of hydrogen and helium with sufficient mass that it can endure nuclear mixture at its core.

Th... ... middle of paper ... ...y result from short-lived massive stars. They are most commonly found in type Sc spirals, but also in the arms of other spiral galaxies and in irregular galaxy, especially starburst galaxies. (”supernova”) Type Ib/c and II-L, and possibly most type IIn, supernovae are only thought to be produced from stars having near-solar metallicity levels that result in high mass loss from massive stars, hence they are less common in older more distant galaxies. The table shows the expected progenitor for the main types of core collapse supernova, and the approximate proportions of each in the local neighborhood. (”supernova”) Works Cited "Supernova."

The Andromeda Galaxy is also the only galaxy noticeable to the naked eye in the Northern Hemisphere. The Andromeda Galaxy is the Milky Way's larget galactic acquaintance and is on course for a collision in the fututre. It is believe that the Milky Way Galaxy and the Andromeda Galaxy, also known as M31, will collide in the future. The Andromeda Galaxy keeps moving toward the Milky Way at about 250,000 miles per hour.The Milky Way and Andromeda are moving toward each other under the pull of gravity. At first, the two galaxies may whirl past or through each other, dragging out long gravitational tails.

Cosmic Nurseries - Mommy, Where do Stars Come From? Since my entire thesis for this paper is about how a star is born, I guess the first thing I should start out with is by telling you exactly what a star is. Stars are self-luminous gaseous spheres. They shine by generating their own energy and radiating it off into space. The stars' fuel for energy generation is the stuff they are made of --hydrogen, helium, carbon, etc.