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All galaxies contain star clusters. A star cluster is a group of stars held together by gravity. Open star clusters are collections of six to thousands of usually young stars. Globular clusters are ball-shaped collections of thousands to millions of very old stars. Galaxies are collections of millions to hundreds of billions of stars, planets, gas, and dust, measuring up to one hundred thousand ly across. They came in different shapes and sizes and are spread across the Universe. In the 1920’s, astronomer Edwin Hubble changed the way in which scientists view the Universe. The four types of galaxies that are categorized by shape are elliptical, spiral, lenticular, and irregular. Elliptical galaxy is a large group of stars that together make
Clusters like NGC 6530 were formed from the same cloud, and as a result have roughly the same age. This makes them of particular interest to astronomers. Because clusters are all formed from the same material, have roughly the same age, and distance from earth, variations in their brightness is only due to their mass ("Open Star Clusters"). This makes them particularly useful for studying stellar evolution. This cluster was first observed by Hodierna in 1654, and later found independently by Flamsteed in 1680 when he discovered the cluster was located within the Lagoon Nebula. Like most open star clusters, NGC 6530 is relatively young; having been formed less than 6 million years ago ("Young Stars Paint Spectacular Stellar Landscape"). It is known to consist of more than a hundred known bright stars, the light of which show very little reddening as a result of interstellar matter from the nebula, this is likely because the cluster is located just in front of the
Space travel began in the 1960s with sending humans on single missions into space. Rockets launched into the air and just the tip would land in the ocean after parachuting back to Earth ("Space Shuttle Program," par. 4). The focus of space exploration changed during the 1980s; shifting from the desire for human space flight to the desire to create a reusable spacecraft. Originally called Space Transportation System (STS), NASA created the Space Shuttle Program (SSP) (Heiney, par. 1-2). It wanted a shuttle that was more economical because it could be launched, landed and relaunched and could gather better information. The 1980s began a new era in space exploration and had one the biggest tragedies in the history of space travel.
Where would the world be without the inventions and ideas of the 1920's? The answer is, no one really knows; however, the inventions and ideas that were brought about in the 1920's are things that are used more than ever today. With the technological advancements made in the 1920's, the invention of the radio, television, automobile, and other minor advancements made the 1920's one of the most important decades of the 1900's.
...f gas, which collapsed and broke up into individual stars. The stars are packed together most tightly in the center, or nucleus. Scientists believe it is possible that at the very center there was too much matter to form an ordinary star, or that the stars which did form were so close to each other that they coalesced to form a black hole. It is argued that really massive black holes, equivalent to a hundred million stars like the Sun, could exist at the center of some galaxies
Even though politicians and historians view political cartoons differently, historians can now look back and truly capture the minds of the American people during the 1920s. This political cartoon, “The Modern Devil Fish,” illustrated by Victor Hugo, was published in a 1925 issue of the Chicago Tribune. This specific cartoon was used as propaganda to promote the Prohibition Party and encourage the support of voters by addressing the usual arguments against the legal status of alcohol. It also was used as propaganda to show the far reaching effects of its use on American society, as demonstrated by the labels on each of the octopus’ tentacles, ranging from ‘partnership with thieves’ to ‘traffic in girls’ to ‘political corruption.’ The fight for prohibition had been an ongoing one, but it had become clear to those rallying to ban liquor that the power of the vote would be the only way to ‘slay’ the saloon monstrosity – pictured here as the knife labeled ‘votes,’ driven into the head of the creature by a hand bearing the name of the Prohibition Party. By destroying the center of the problem, saloons, the knife wielding political party is destroying all of the problems connected to it. In reality, the issues on each tentacle were far from solely the fault of alcohol consumption, but the Party was making an effort to get votes and inspire support, thus exaggerating the point of the prohibition issue. The hope of Hugo as he illustrated this cartoon was clear – that people who understood it would recognize the evils of a nation which does not prohibit saloons and the like subjects itself to by not utilizing the ‘knife’ of Prohibition Party votes. The cartoonist with his drawings could say more in one cartoon than could be said by a spee...
For example, the Cumulo de Pegaso is located off the tip of Pegasus’s nose and is known for its intensely bright center (Pommier, Rod). Cumulo de Pegaso was discovered by Jean-Dominique Maraldi in 1764 (“Pegasus Constellation”). Unlike Cumulo de Pegaso which can be seen with a small-telescope, Stephan’s Quintet requires a large telescope (Bakich, Michael E). Stephan’s Quintet is the first compact group of five galaxies. Edouard Jean-Marie Stephan discovered Stephan’s Quintet in 1877 (Berman, Bob.). In 1784, William Herschel discovered the Propeller Galaxy. The Propeller Galaxy is undergoing star forming activity, resulting in the S-shape it was named after “Pegasus Constellation”). Also in 1784, William Herschel discovered the spiral galaxy of NGC 7331. NGC 7331 resembles the Milky Way in size and structure (“Pegasus Constellation”). Lastly, Einstein’s Cross includes four quasars that show the phenomenon of gravitational lensing. Einstein predicted gravitational lensing in his general theory of relativity, claiming that gravity would be able to bend light. This prediction led to Einstein’s Cross’s name (“Pegasus
lifetime. Some of Edwin Hubble's greatest accomplishments were: Edwin Hubble proposed a classification system for nebulae, which are fuzzy little patches of light that are up in the sky. He discovered a variable star, called the Cepheid. It is located in the Andromeda Nebulae. Edwin Hubble settled decisively the question of the nature of the galaxies. Edwin Hubble's distribution of galaxies was determined to be homogeneous in distance. Edwin wanted to classify the galaxies according to their content, distance, shape, and pattern of brightness. By observing redshifts Edwin saw that galaxies were moving away from each other at a rate constant to the distance between them (this is known as Hubble's Law).
Every day we look into the night sky, wondering and dreaming what lies beyond our galaxy. Within our galaxy alone, there are millions upon millions of stars. This may be why it interests us to learn about all that we cannot see. Humans have known the existence of stars since they have had eyes, and see them as white glowing specks in the sky. The mystery lies beyond the white glowing specks we see but, in the things we cannot see in the night sky such as black holes.
By 1936, astronomers had realized that the hazy balls they sometimes saw in their telescopes, which looked like stars obscured by gas, were actually galaxies (Hibbison).
Stars are born in the interstellar clouds of gas and dust called nebulae that are primarily found in the spiral arms of galaxies. These clouds are composed mainly of hydrogen gas but also contain carbon, oxygen and various other elements, but we will see that the carbon and oxygen play a crucial role in star formation so they get special mention. A nebula by itself is not enough to form a star however, and it requires the assistance of some outside force. A close passing star or a shock wave from a supernova or some other event can have just the needed effect. It is the same idea as having a number of marbles on a trampoline and then rolling a larger ball through the middle of them or around the edges. The marbles will conglomerate around the path of the ball, and as more marbles clump together, still more will be attracted. This is essentially what happens during the formation of a star (Stellar Birth, 2004).
The idea behind the Solar Nebular Hypothesis is that the solar system was condensed from an enormous cloud of hydrogen, helium, and a few other elements and rocks. Around five billion years this cloud of materials began to spin and contract together into a disk shape under their own gravitational forces. The particles started combined together, protoplanets, to eventually form planets. A great mass of the material eventually began to form together, protosun, and make up the sun.
Paul Bogard in the given excerpt discusses the value of darkness and the harms of light pollution.
The Andromeda Galaxy being 220,000 light years across is the biggest of its local galaxy group which includes the Milky Way Galaxy, Triangulum Galaxy, and about 44 smaller galaxies. The Andromeda Galaxy contains about (1 trillion*10to the 12th power) stars, which is more then double the estimated 200- 400 billion stars located in our own Milky Way Galaxy. Along with this the Andromeda Galaxy has a brightness magnitude of 3.4 making it one of the brightest of all the Messier Object group.
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. Our Sun is one of the billions of stars in our galaxy, and our eight planets revolve around this star in only a tiny part of our galaxy. “The Earth’s solar system is believed to exist very close to the Galaxy’s galactic plane, due to the fact that the Milky Way essentially divides the night sky into two virtually equal hemispheres” ("All About the Milky"). It definitely makes people second guess the fact of there being life on other planets.
The 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 of dust, gases (mainly 75% Hydrogen and 25%Helium), atoms, about 100-200 billion stars, interstellar clouds and planets, attracted to the center by gravitational force of attraction. Based on recent research, 170 billion galaxies have been estimated to exist, with only tens of thousands been discovered (Deutsch, 2011).