...Life Cycle of Stars The Birth of a Star In space, there exists huge clouds of gas and dust. These clouds consist of hydrogen and helium, and are the birthplaces of new stars. Gravity causes these clouds to shrink and become warmer. The body starts to collapse under its own gravity, and the temperature inside rises. After the temperature reaches several thousand degrees, the hydrogen molecules are ionized (electrons are stripped from them), and they become single protons. The contraction of the gas and the rise in temperature continue until the temperature of the star reaches about 10,000,000 degrees Celsius (18,000,000 degrees Fahrenheit). At this point, nuclear fusion occurs in a process called proton-proton reaction. Briefly, proton-proton reaction is when four protons join together and two are converted into neutrons; an 4He nucleus is formed. During this process, some matter is lost and converted to energy as dictated by Einstein's equation. At this point, the star stops collapsing because the outward force of heat balances the gravity. The Hydrogen Burning Stage The proton-proton reaction occurs during a period called the hydrogen-burning state, and its length depends on the star's weight. In heavy stars, the great amount of weight puts a large amount of pressure on the core, raising the temperature and speeding up the fusion process. These heavy stars are very bright, but only live for a short amount of time. After the energy from this deuteron-hydrogen fusion process...
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...of these 2. Which of the following can't be considered an acceptable hypothesis?" A. Dark matter, (invisible matter which still has gravitational attraction), determines the orbits of stars in the the galaxy B. Mass increases with velocity C. Matter came into existence together with time D. The megagalaxies of the universe will become invisible to each other in time. E. all are acceptable hypotheses 3. A theory is an integrated explanation of numerous “proven”_____. A. facts B. laws C. controls D. hypotheses E. guesses 4. What is the correct sequence of steps in the scientific method? I. State a problem II. Analyze and interpret data III. Develop a hypothesis IV. Share the results with other scientists V. Design and perform experiment to test the hypothesis A. I – II - III - IV – V B. III – I - V – II – IV C. V – IV – III – II – I D. I – III – V – II – IV E. V – II – I – III - IV 5. Ptolemy's model sought to explain retrograde motion by _____. A. adding circles to epicycle orbits B. adding circles to elliptical orbits C. adding epicycles to elliptical orbits D. adding epicycles to circular orbits 6. Due to retrograde motion some planets will rise in the west and set in the east. True or False 7. Which of the following is correctly ordered from largest to smallest in size? A. Moon, neutron star, white dwarf, galaxy B....
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...Black holes are known to have a large density and mass, with a strong gravitational pull. However, they can be big or small, with the smallest being just one atom. Even though no light can be released, space stations have developed special tools to help find black holes. The special tools help distinguish how stars react near a black hole and how they react away from a black hole. Scientists have also found a different way to detect black holes. Since black holes have strong gravitational pull, stars and gases around will funnel towards the black hole and start orbit around it. Black holes commonly appear when a star begins to die. There are two types of black holes: stellar and...
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...Evolution A star begins as a very light dispensation of interstellar gases and dust particles over a distance of a few twelve lightyears. Although there is intensely low pressure existing between stars, this dispensation of gas exists instead of a real vacuum. If the density of gas becomes bigger than 0.1 particles per cubic centimeter, the interstellar gas grows uncertain. Any small alteration 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 is environment and retransmits it as visible and infrared light. These clouds...
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...The Veil Nebula formed about 8,000 years ago after the death of a star 20 times the size of the Sun in a supernova explosion. Now, a new set of Hubble Telescope videos reveal clear images of its violent beauty. The explosion, lightning fast, plowed into a wall of cool, dense interstellar gas, emitting light. The Nebula is along the edge of a large bubble of low-density gas that was blown into space by the dying star before it exploded. The remnants of the destroyed star are multicolored and stunning, showing a colorful cloud of material that is 110 light years wide and about 2,100 light years from Earth. It’s located in the constellation called Cygnus, or The Swan Nebula. Where Does the Color Come From? According to the European Space Agency,...
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...a fairly ordinary but large star. b. The Sun is the focal point of our solar system, because all of the planets orbit the Sun. 2) What is our Milky Way galaxy and the sun’s position in it? a. The Milky Way galaxy is where our solar system is located in the universe. b. The Milky Way galaxy is home to over 100 billion stars and the Sun is one of those stars. 3) What is the Big Bang and what does it say about the age of the universe? a. The Big Bang is when the universe began. b. The Big Bang is thought to have happened about 14 billion years ago. 4) What is meant by the phase “looking out in the universe is looking back in time?” a. When viewing the universe we see a vast amount of stars. b. The light from stars must travel great distances to reach us, and these distances take years. c. So when we see a star we are seeing the star as it was when the light first started traveling. b. Where are we in the universe? 1) What is Earth’s place in the solar system? a. The Earth is our home. b. The Earth is the only planet known to sustain human life. 2) How close are the nearest stars to the Sun as compared to the distance between the Sun and the Earth? 3) How large is our Milky Way galaxy? a. The Milky Way galaxy is home to our solar system. b. The Milky Way galaxy has a 100,000 light-year diameter. 4) How many stars are estimated to exist in our galaxy? a. There are roughly 100 billion stars in the Milky Way Galaxy. b. So many stars that it would take someone’s...
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...brightest appearing stars in the sky would give you a biased luminosity scale and an unrepresentative sample of stars. -The stellar parallax measures the relative distances from stars to different positions of the Earth in order to measure luminosity. It is done by using distant stars as a fixed reference system so that if a star is observed in respect to the distant stars today, and then measured again in six months, a small shift in movement will be recorded. It is absolutely necessary for there to be “distant stars” or less bright stars as a frame of reference otherwise the angle measurements would have nothing to compare against. Thus, it creates a biased scale of recorded luminosity. 2. Explain the overall concept of pressure support (against gravity) in stars and why stars are unstable if they are not generating energy in their cores. -The concept of pressure support can be explained through the internal gas pressure. The internal gas pressure is attempting to expand and dissipate our ball of gas, while the self-gravity of the gas (due to its mass) is trying to collapse the ball. As the gas gets hotter, the internal gas pressure increases. Then, it reaches a point of stabilization between gravity and pressure support. -Stars are unstable if they are not generating energy in their cores because the energy generation prevents the collapse of the star. Energy generation is occurring in its core, and this provides gas pressure which prevents collapse of the star. Thus, if the...
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...Earth will not be able to support life if the Sun becomes a giant star. Giant stars have large radii as their name implies. When the Sun becomes a giant star, it may become so large as to engulf Earth, in which case the planet will be destroyed. Even if this does not happen, the sun will expand so far out that the temperatures on Earth will become extremely high so that all oceans will evaporate away, and there will be no water left on Earth. So, no life which depends on water will be able to survive.Our modern, technologically complex systems - including communications, transportation, and electrical power systems - can be disrupted and damaged by space weather storms. Exposure to radiation can threaten astronauts and commercial air travelers alike, and has affected the evolution of life on Earth. Space weather probably alters the weather and climate on our planet, though we don't yet have a precise understanding of those influences. The Northern Lights are a visible result of a magnetic storm happening in our...
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...In the article “Four Starry Nights”, Anna Frebal talks about stars in ultra faint dwarf galaxies that astronomers have spotted in the past ten years. Her research primarily revolves around this topic. She begins by telling us that stars in dwarf galaxies are some of the oldest stars because of the proportion of elements that they carry. She also states that a new generation of stars form from gaseous clouds that are enriched by heavier elements, elements like lithium. Frebal furthermore tells us about how ultra faint dwarf galaxies have fewer stars than their luminous peer, but they have higher proportions of metals and that they are most likely relics from a long time ago. Additionally, Frebal has discovered that the ribbons of starlight that...
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...Name Instructor Course Date Dark Nebulae Dark nebulae are nonluminous nebulae that are observable since it obscures light from other sources. Nebulae are diffuse clouds of interstellar dust and gas. The shape, size, and characteristics of nebulae may vary significantly because some are the remains of dead stars and others are star nurseries. Dark nebulae are found in areas with no nearby stars. These clouds do not emit or reflect enough light for them to be visible. In fact, the view from the stars behind them is usually blotted out by the dust particles. This paper will exclusively explore on dark nebulae. Normally, these clouds range from 1-10 AU and are less dense than the deepest vacuum in the laboratories of the Earth. They are also thick such that they obscure light from the stars behind them. However, the size of these clouds can be from a few light years up to 600 light years. Additionally, the total mass of dark nebulae can reach several million masses of solar. These clouds can appear to be big depending on the number of stars in it. If there are many stars, the clouds will appear huge, but it can appear small if there are a few stars in it. These clouds existed from a long time ago. Claudius Ptolemaeus did the first record of stars that appeared to be nebulous around 150 AD. Since then, many astronomers have continued discovering these clouds until an American astronomer Beverly Turner Lynds compiled and published a survey of dark nebulas in the year 1960. However...
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...million years ago would still be there today. Because the moon has little to no atmosphere there isn’t any water to create erosion and there is no wind. The temperatures of the moon vary from day to night. During the day the temperature is approximately +300°F and night time is -270°F. The temperature is this way due to the fact there is no atmosphere to protect against the sun and keep it warm at night (MoonPhases.Info, 2010-2011). The coolest cosmic entity in the sky is the moon. At night when the moon is out, it’s the first thing that lights up the night sky. It takes 27.3 days for the moon to turn on its axis and to orbit the earth. Due to this it makes the moons phases and orbit a mystery (Charles Q. Choi, 2013). Below is a photo of the moon. Some things in life are just beautiful. It’s interesting to know there are craters, mountain ranges, rilles, and lava plains on the moon. The moon doesn’t construct its own light, it is bright due to the mirror image from the sun (National Earth Science Teachers Association, 2012). Due to the gravitational pull between the earth and the moon, there are some fascinating effects that are produced. Like...
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...A. Constellation: Libra, The Scales Libra represents a balance scale. They gave it this name because the sun passed across the face of the constellation at the time of the autumnal equinox in September, when day and night are of roughly equal length, so the heavens are balanced. (StarDate, Website) Libra is the only zodiac constellation that represents an object, not an animal or a character from mythology. This constellation is best seen in June at 9:00 PM. B. Stars/Galaxies The Libra constellation occupies an area of 538 square degrees and contains three stars with known planets. Libra is a relatively faint constellation, without any stars of first magnitude. The brightest stars are Alpha, Beta, Gamma and Sigma Librae which form a quadrangle...
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...in about 150 BC He ranked the stars he could see in terms of their brightness, with 1 representing the brightest down to 6 representing the faintest. Modern astronomy has extended this system to stars brighter than Hipparchus' 1st magnitude stars and ones much, much fainter than 6. As it turns out, the eye senses brightness logarithmically, so each increase in 5 magnitudes corresponds to a decrease in brightness by a factor 100. The absolute magnitude is the magnitude the stars would have if viewed from a distance of 10 parsecs or some 32.6 light years. Obviously, Deneb is intrinsically very bright to make this list from its greater distance. Rigel, of nearly the same absolute magnitude, but closer, stands even higher in the list. Note that most of these distances are really nearby, on a cosmic scale, and that they are generally uncertain by at least 20%. All stars are variable to some extent; those which are visibly variable are marked with a "v". What are apparent and absolute magnitudes? Apparent is how bright the appear to us in the sky. The scale is somewhat arbitrary, as explained above, but a magnitude difference of 5 has been set to exactly a factor of 100 in intensity. Absolute magnitudes are how bright a star would appear from some standard distance, arbitrarily set as 10 parsecs or about 32.6 light years. Stars can be as bright as absolute magnitude -8 and as faint as absolute magnitude +16 or fainter. There are thus (a very few) stars more than 100 times brighter than...
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...a red supergiant star in the Milky WayGalaxy and the sixteenth brightest star in the night time sky. It is sometimes listed as 15th brightest, if the two brighter components of the Capella quadruple star system are counted as one star. Along with Aldebaran, Regulus, and Fomalhaut, Antares comprises the group known as the 'Royal stars of Persia'. It is one of the four brightest stars near the ecliptic. It is the brightest star in the constellation Scorpius, and is often referred to as "the heart of the scorpion". Antares is a slow irregular variable star with an average magnitude of +1.09.[3] Antares is the brightest, most massive, and most evolved stellar member of the nearest OB association. Antares is a member of the Upper Scorpius subgroup of the Scorpius-Centaurus Association, which contains thousands of stars with mean age 11 million years at a distance of approximately 145 parsecs (470 light years). Antares is visible in the sky all night around May 31 of each year, when the star is atopposition to the Sun. At this time, Antares rises at dusk and sets at dawn as seen at the equator. For approximately two to three weeks on either side of November 30, Antares is not visible in the night sky, because it is near conjunction with the Sun;[13] this period of invisibility is longer in the Northern Hemisphere than in the Southern Hemisphere, since the star'sdeclination is significantly south of the celestial equator. Antares has a secondary, or companion star, Antares B, that...
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...Science of Stars This paper is about the science of the stars. In this paper I will address how astronomers determine the composition, temperature, speed, and rotation rate of distant objects. I will briefly explain the properties of stars in the H-R diagram from Chapter 15 of the course textbook “The Cosmic Perspective”. I will also summarize the lifecycle of the Sun and identify where the Sun is in its lifecycle. Studying Distant Objects Astronomers study light which comes from distant objects to determine its composition, temperature, speed, and rotation of distant objects. This process is called spectroscopy. Spectroscopy was first used to study celestial objects in 1863 by William Higgins. By using this process he discovered the Sun and most stars are primarily composed of hydrogen gases. By using the spectroscopy technique it was discovered that different objects give off and absorb different spectrums of light. Where the object falls in the spectrum of light can be determined by examining its peak intensity at each wave length of light. The light helps us to determine an objects composition, temperature, and rotation. There are three types of spectra used to evaluate light. Objects which absorb light at different wavelengths are referred to as absorption spectrum. The intensity of light drops in objects which absorb light and therefore appear as dark lines on a rainbow of colors. Objects such are stars, planets with atmospheres, and galaxies absorb light and...
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