Galaxies are large groups of stars, dust, and gas. Galaxies contain planets, star system and clusters, and interstellar clouds. In between these objects, there’s a sparse interstellar medium of gas, dust, and cosmic rays. There are supermassive black holes located at the center of most galaxies. Supermassive black holes are the largest type of black hole. Galaxies that have less than a billion stars are considered “small galaxies”. Galaxies are categorized according to their shape. There are three
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. Galaxies have been categorized throughout history
own galaxies. The mass of our giant galaxy is somewhere between 750 billion and one trillion solar masses. The diameter is estimated to be about 100,000 light years. The galaxy has three main components: a disk, in which the solar system resides, a central bulge at the core and an all encompassing halo. The disk of our galaxy exhibits it’s spiral structure and is part of the prominent nuclear region which is part of a notable bulge/halo
Our galaxy also known as the Milky Way, with reference to a Greek word galaktos mean- ing milk, is the most studied galaxy. It is also referred as the Galaxy. A part of it can be seen on clear dark nights as a faint white band of light stretching across the sky. Study of its constituent stars will help to understand its structure and evolution. The structure of it is the intense subject of many studies for the last four centuries. A brief account of it is given here. In 1610s, Galileo Galilei using
Universe is a collection of millions of galaxies and extends beyond human imagination. After the big bang, the universe was found to be composed of radiation and subatomic particles. Information following big bang is arguable on how galaxies formed, that is whether small particles merged to form clusters and eventually galaxies or whether the universe systematized as immense clumps of matter that later fragmented into galaxies (Nasa World book, 2013). A galaxy is a massive area of empty space full
A Galaxy is an enormous collection of billions of stars, gas and dust held together by the force of gravity. Our sun and all the other visible stars in the night sky belong to the Milky Way galaxy. The entire Milky Way galaxy itself contains over 200 billion stars with an average separation of 5 light years between each of them. Similarly, there are billions of other galaxies are existing in our unimaginably vast Universe. Galaxies come in different shapes and sizes. They were first classified according
the 1930s, based on Edwin Hubble's discovery that distant galaxies are receding. Hubble measured the distances to a large number of galaxies (based on the observed brightness of certain stars within them), and compared these distances with their electromagnetic spectra. As it turned out, more distant galaxies had the features in their spectra (spectral lines) shifted to lower frequencies in a linear manner: that is, more distant galaxies exhibit greater redshifts. The only known mechanism for generating
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. 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
Sabdy Mariscal IPC-4B Astronomy Astronomy is the science of space beyond earth’s atmosphere like stars, comets, galaxies, nebula, and comets – as well as the large scale of properties of the universe also known as the big picture. However I’m only going to write about stars, comets, galaxies, and the nebula because I think those are the most interesting aspects of astronomy. Stars have different size, color, and temperature. There are different types of stars; some are smaller than the earth and
method used to discover the first quasars was based on coincidences between a strong radio source and a point-like optical source. Since each radio source was associated with a star it was originally thought that quasars were objects within the galaxy hence the term 'radio stars'. Quasars or quasi-stellar radio source, from the method by which they where originally discovered: as stellar optical counterparts to small regions of strong radio emission. With increasing spatial resolution of radio
the matter that we see today which includes stars and galaxies. Due to the fact that dark matter doesn’t interact with the electromagnetic force, dark matter doesn’t absorb, reflect or emit light. Dark energy doesn’t have local gravitational effects but it does affect the universe as a whole. The importance of dark matter and dark energy is that they make the majority of the mass in the universe. Dark matter and energy are important to how galaxies function and survive. Dark matter must help make up
the interaction of two or more galaxies. The results of a galactic interaction are so varied that each event is unique. Therefore, only a select few examples will be described in the following pages. An examination of the term “galactic interaction” does not immediately convey much in the way of understanding as to exactly what happens during one of these events. The problem is that the word “interaction” is fairly ambiguous, yet it must be so because two galaxies can interact in so many ways that
suddenly increases many millions of times its normal level. The supernova came around the 1930’s by Walter Baade and Fritz Zwicky. Supernovas are very rare to see they happen every 50 years in the Milky Way. Supernovas cannot be predicted in our galaxies it is impossible.(“Supernova”) A supernova is an explosion of a massive supergiant star. It may shine with a brightness of 10 billion suns! The total energy output may be 10^44 joules, as much as the total output of the sun during its 10 billion
Discussing the Hypothesis of a Supermassive Black Hole in the Milky Way Galaxy There is evidence that supports the hypothesis that the Milky Way Galaxy has a massive black hole at its core. At the center of our very own galaxy is a mysterious source of energy. Vast amounts of radiation pour from this compact source which may be a Supermassive Black Hole. Astronomers found an intense radio source with strings of other radio sources clustered about it in the direction of the galactic center. The
these are actually small galaxies gravitationally bound to the Milky Way like moons around a giant planet. The two Clouds of Magellan are like binary stars that gravity draws together to form a satellite galaxy. Of all the galaxies in the entire Universe these are the closest to our galactic system. About 170,000 light-years away from the Milky Way galaxy lie the Large Magellanic Cloud. With only 15 billion young bright stars, it is just one-quarter the size of our own galaxy. During the winter of 1987
Future of Our Galaxy Galactic Millenium What Does the Future Hold? (adopted from an article by Greg Laughlin and Fred Adams, "Celebrating the Galactic Millennium", Astronomy November 2001) Not too long ago, we were looking forward to the New Millennium. To many of us, this was an important event of our lives. On a larger scale, however, the New Millennium looks insignificant. "If we adopt an astronomical perspective, however, a much larger and more distant celebration remains on the schedule-the
discovery of the vast universe, that exists outside our galaxy, began with Edwin Hubble’s discovery of a Cepheid Variable star in Andromeda, which he used to measure the distance to our neighbouring galaxy (Bennett et al. 109). This was instrumental in establishing Hubble’s law or the theory that the universe is expanding and galaxies are moving away from the Milky Way (Bennett et al. 109). However, Andromeda poses a contradiction; while other galaxies are moving away from the Milky Way, Andromeda is actually
Astronomy: A Fad Science? NOTE: This paper was written for an English class and a non astronomy audience. Thus, several arguments were left out to make the material easier to understand for the target audience. These arguments would include (but are not limited to) dark energy, dark matter, and the inflationary model of the universe. If I later have time I may revise this paper to cover such topics and be more comprehensive. Science is a field that prides itself on being objective. To help
"Quantized Galaxy Red shifts" by William G. Tifft & W. John Cocker, University of Arizona, Sky & Telescope Magazine, Jan., 1987, pgs. 19-21. I thank Mark Stewart for this material: As the turn of the next century approaches, we again find an established science in trouble trying to explain the behavior of the natural world. This time the problem is in cosmology, the study of the structure and "evolution" of the universe as revealed by its largest physical systems, galaxies and clusters
In 1916, the German astronomer Karl Schwarzchild attempted to theorize how a star could shrink to become what he called a "Black Hole". Schwarzchild predicted that our sun would have to shrink to less than two miles in radius. He also predicted that even though the sun had shrunk its mass and weight would remain the same, which means that the planets would continue on their orbits, uneffected. Schwarzchild still questioned if stars could become this compact. In 1934 W. Baade and F. Zwicky predicted