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 to their structure by Edwin Hubble in 1926 (Fig).
Elliptical galaxies, designated E, are ellipsoidal shaped and range from nearly perfect spheres (E0) to the flattest (E7). They contain old stars and have very little gas and dust. Elliptical galaxies show very little rotation compared to other types of galaxies. These galaxies are the most numerous among all types of galaxies.
…show more content…
Most spirals consist of a rotating flat disc containing stars, dust and gas, and a central collection of stars known as the bulge. Hubble itself classified the various spiral galaxies into groups of Sa, Sb, Sc and so on. This naming is in accordance with the decreasing order of the importance of the central bulge compared to the surrounding disc and this can be inferred from the fig. Milky Way and our nearest galaxy M31 belong to the group Sb. Some spirals have a bar-shaped structure in their central region. They are called barred spirals and are grouped as SBa, SBb, SBc and so on.
Irregular Galaxies (Irr) have no regular geometric shape. They usually contain gas and dust, mostly bright young stars and clouds of ionized
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
Distances so vast that the light from those areas in space is billion years old. Illingworth was able to see these ancient giants with the Hubble Space Telescope. A telescope that is high above the atmosphere, because it can distort the image. 100 sextillion miles or 17,010,779,502.32 light years is the most distant galaxy Illingworth
Shapley said that because other spiral nebulae looked different than our own galaxy, they had to be different than ours. Curtis didn't say anything about that but he did say that the lines in those nebulae proved that they were made up of many stars, just like our Milky Way. Curtis was right, and Shapley was only wrong because he didn't know that astronomers really can't get the same view of our own galaxy as we can of other galaxies. It's like trying to see your whole body without a mirror. Your eyes can only do so
Waller, William H. The Milky Way: An Insider's Guide. Princeton, N.J: Princeton UP, 2013. 42+. Print.
2, Alter Dinsmore, Cleminshaw H. Clarence, Philips G John. Pictorial Astronomy. United States: Sidney Feinberg, 1963.
The Sun is a huge, bright sphere that is mostly made up of gas that is about 5 billion years old. The Sun is the closest to the Earth, it is 145 million km distant (this distance is called an Astronomical Unit). The next closest star is 300,000 times further away. There are probably millions of similar stars in the Milky Way galaxy (and even more galaxies in the Universe), but the Sun is the most important to us because it supports life on Earth.
The extreme brightness of the O-type and B-type stars, coupled with the Earth’s atmosphere, has always made high-resolution imaging of the star-forming region difficult. But recent advances in adaptive optics and the repair of the Hubble Space Telescope have allowed for incredible detail into the center of the dust cloud. 3 The technological advances have also helped reveal several faint stars within the center of the nebula.
It is obvious that Raskolnikov did not kill Alyona. Nikolai did. He confessed, didn't he? Sure, sure, I know what you're saying: Raskolnikov confessed too. But it is obvious that his confession was not a true confession. Raskolnikov had seen Nikolai's true confession, and was so moved that he decided he'd like to try confessing too. And one must not overlook the Christ symbolism in the novel. Raskolnikov is the obvious Christ-figure; he's poor, he's generous, he's schizophrenic. It all adds up. Raskolnikov is Christ's second incarnation but nobody realizes it's Him. Kind of sad. One should not overlook Raskolnikov's superior man theory. Nikolai, on the other hand, is the scum of the earth. He's a minor character, and minor characters always commit murders in books. What else do they have to do? One should not only look at the psychology of the characters in the novel, but of the author as well. Dostoevsky wouldn't write a story about some vile murderer. No. Dostoevsky was a good Christian writer. C&P is a handbook for becoming a Christian, not some murder psychology thriller.
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).
A star begins as nothing more than a very light distribution of interstellar gases and dust particles over a distance of a few dozen lightyears. Although there is extremely low pressure existing between stars, this distribution of gas exists instead of a true vacuum. If the density of gas becomes larger than .1 particles per cubic centimeter, the interstellar gas grows unstable. Any small deviation in density, and because it is impossible to have a perfectly even distribution in these clouds this is something that will naturally occur, and the area begins to contract. This happens because between about .1 and 1 particles per cubic centimeter, pressure gains an inverse relationship with density. This causes internal pressure to decrease with increasing density, which because of the higher external pressure, causes the density to continue to increase. This causes the gas in the interstellar medium to spontaneously collect into denser clouds. The denser clouds will contain molecular hydrogen (H2) and interstellar dust particles including carbon compounds, silicates, and small impure ice crystals. Also, within these clouds, there are 2 types of zones. There are H I zones, which contain neutral hydrogen and often have a temperature around 100 Kelvin (K), and there are H II zones, which contain ionized hydrogen and have a temperature around 10,000 K. The ionized hydrogen absorbs ultraviolet light from it’s environment and retransmits it as visible and infrared light. These clouds, visible to the human eye, have been named nebulae. The density in these nebulae is usually about 10 atoms per cubic centimeter. In brighter nebulae, there exists densities of up to several thousand atoms per cubic centimete...
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.
Michael Korotkov Capstone Period 2 11/17/14 Planes of satellites in galaxies similar to the Milky Way A new discovery may have “implications for our theories of gravity”. The Milky Way and Andromeda have planes of satellites. However, these planes should not exist according to the standard theory of how galaxies are formed. It is important to know why these plane of satellites exist exist because it influences our understanding of how the universe works. By using data from astronomical surveys, it is possible to test a large sample of galaxies, and identify which galaxies have planes of satellites around them, possibly yielding the explanation as to why the Milky Way and Andromeda have planes of satellites.
The first person to ever observe the Milky Way was Greek philosopher, Democritus, who said the galaxy may consist of distant stars. In 1610, Galileo Galilei used a telescope to study the Milky Way and came to the conclusion that it was composed of billions and billions of faint stars. Then, in 1750, Thomas Wright c...
Generally, the universe began as a composition of radiation and subatomic particles, which proceeded with galaxies formation. Galaxies are made up of hydrogen, helium, 100-200 billions of stars, planets and most having a black hole at the center, which attracts everything present in galaxies by force of gravity. Galaxies can be classified as either spiral (Milky Way- galaxy which human kind has been found to exist), elliptical, lenticular and irregular, where the structure is determined by neighboring galaxies with most galaxies are moving away from each other. Classification of galaxies is being conducted by online programs such as Galaxy zoo, using pictures from telescopes and is making significant progress.
...enith (straight overhead position). Two galaxies which are believed to revolve around our own are the Small and Large Magellanic Clouds. Only visible from the Southern Hemisphere, Magellan, the famous European explorer, was the first to describe these galaxies.