...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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...and chose 30 bright stars from the drop down menu and then also check, “specify a star”. Your screen now looks like this: You are to select two stars for this exercise – GL171.1 and GL 244. Upon selecting a star, click on step 2 - Measure Stellar Parallax to get this measuring screen – every 6 months a measurement is made and plotted in what is called “Error Histogram”. These errors are caused by making measurements through our atmosphere. You need to wait until you have about 40 measurements until you have a reasonable certain average value in the error histogram. That average value is the stellar parallax angle for that star. Once you know this angle the distance to the star (and hence its luminosity) can be determined. Enter your answers to the questions below in the provided table (the response cell will expand with your typing) Question: Your Response a) What are the angles for GL 244 and GL 171.1 GL 244= 0.393 GL 171.1 = 0.043 b) Which one of these two stars has the more accurate determination of the parallax and why? GL 244 has the more accurate determination because it is much closer and has a much higher parallax then GL 171.1. c) Explain selecting only the brightest stars in the sky for parallax measurements would give you a biased sample There needs to be less bright stars or more distanced stars used as a frame of reference otherwise the angle would have nothing to compare against the bright stars. 2. Explain why stars are unstable (that...
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...Astronomy 2B03: Lecture 2: What’s Out There? * Objects in the universe come in a hierarchy of scales and sizes: * Planets * Stars * Galaxies * The universe as a whole * These scales are so different from one step to the next that they are incredibly hard to comprehend all at once – no “everyday” experience to refer them to * If the Earth were a basketball how big would the moon be? Tennis ball * How many Earths would fit into the Sun? ~ 1 million * How many Jupiter’s would fit inside the Sun? 900 * How many Moons would fit inside the Earth? 50 * If we say the distance from here to Toronto (71 km) represents the distance between the Earth and the Sun, how far are we from Pluto? From Hamilton to Mexico, or from Hamilton to Calgary * If we say the distance from here to Toronto represents the distance between the Earth and the Sun, how far is the Earth from the Moon? From here to the edge of campus (Sterling and Forsyth) * If we say the distance from here to Toronto represents the distance between the Earth and the Sun, how big is the Earth? 3 meters * If we say the distance from here to Toronto represents the distance between the Earth and the Sun, how far is the Sun from the next nearest Star? 1/10th the distance from the Sun to Earth Lecture 3: The Earth: * Our starting point and only home * Both land and water * The only planet to have liquid water at its surface * Atmosphere: dense...
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...Assignment No. 1 Case Analysis (Class or Mass) A Report Submitted to By Executive Summary Neptune Gourmet Seafood, North America's third-largest seafood producer. Neptune was an upmarket premium brand, and Neptune wants to preserve its premium image among customers. Recently they made huge investment in technology to improve catching processes but in turn it leads to problem of piling up of inventory. The solution of this problem depends up on the nature of problem; if problem is Neptune specific and temporary then they can do away with it by dumping it into some other market, but if it is industry wide phenomenon then they must launch a low price brand. Table of Contents Serial No.ContentsPage No.1Situation Analysis52Problem Statement53Options54Criteria65Evaluations of options66Recommendations77Action Plan7 Situational Analysis Neptune Gourmet Seafood, North America's third-largest seafood producer. It has nearly 4% market share. Neptune was an upmarket premium brand. They are having tagline "The Best Seafood on the Water Planet" and they adhere to that. Neptune focus was always on to preserve its premium image among customers by improving their product continuously The company reached its consumers, who were extremely demanding, through various channels. Neptune generated about 30% of its revenues by selling frozen and processed fish products to U.S. grocery chains. The Neptune's Gold line of seafood products...
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...clearly not enough to stop the expansion of the universe. However, they have discovered over the past several decades that there may be additional matter hidden from view.1 This raises some important questions. What is this dark matter made of? How can it be detected? Astronomers first found substantial observational evidence of unseen matter in the early twentieth century when studying the galaxy M31.2 They discovered that the velocity curve for the outer limbs of the galaxy, which should drop off with increasing radius as mandated by Kepler's Laws and the Virial Theorem, leveled off at approximately 200 km/s. This observation was confirmed in the early 1970’s when radio astronomers found that hydrogen gas at the edge of galaxies moved with roughly the same velocity as hydrogen gas at the center of galaxies. If the visible matter seen in galaxies is the only source of mass then the observed uniform velocity of hydrogen gas is a direct violation of Kepler’s Laws and the conservation of angular momentum. Thus, the simplest explanation (which is usually the correct one) is that the visible matter in galaxies doesn’t account for all of the mass! This claim suggests that most of the mass in the universe, as much as 90%2, is contributed by unseen or “dark” matter. So, what is dark matter made of? There is no reason why dark matter has to be made of one single material. It is likely that there are different types of dark matter. Dark matter candidates are generally divided into...
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...Chapter 10 : The Sun THE SUNS ATMOSPHERE * the sun is so hot that it neither has a liquid or solid matter anywhere inside of it * moving down into the sun there is denser and hotter masses Photosphere (“sphere of light”) * The photosphere is the innermost of layer of the three layers that comprise the suns atmosphere * A gas layer of the sun that has the most visible light * It is about 400 km thick * Density of the photosphere is low by the earth standards about 0.01% as the air we breathe * Photosphere has a blackbody spectrum that corresponds to an average temp of 5800K * The photosphere appears darkest toward the edge or limb of the solar disk , a phenomenon called limb darkening, * This occurs b/c we see regions of different temp at different depths of the photosphere Granules * lightly colored convection features about 100 km in diameter seen constantly in the solar photosphere * time lapse photography shows that granules form, disappear then reform in cylces that last several minutes Chromosphere (“sphere of color”) * is a dim layer of less dense stellar gas that is above the photosphere * It is the layer we normally see * Astronomers can also study the chromosphere through filters that pass light with specific wavelengths strongly emitted by it – but not by the photosphere – or through telescope sensitive to nonvisble wavelengths that the chromosphere emits intensely Spicules - Are...
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...Stellar 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...
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...speed of light. Either way we know what black holes can cause the one question that every person may ask is, “how do black holes form in space?” So from all the scientists that have been working on this question, the one answer they have is that black holes form when a massive star collapses upon itself which can cause a supernova that can blast the star in various pieces into space. WHAT IS A...
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...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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...* Which of the following is not a general difference between a planet and a star * All planets are made of rock and all stars are made of gas. * Our solar system consists of _________. * the Sun and all the objects that orbit it * A typical galaxy is a _________. * collection of a few hundred million to a trillion or more stars, bound together by gravity * Which of the following best describes what we mean by the universe? * The sum total of all matter and energy * What do astronomers mean by the Big Bang? * The event that marked the beginning of the expansion of the universe * What do we mean when we say that the universe is expanding? * Average distances between galaxies are increasing with time. * Based on observations of the universal expansion, the age of the universe is about _________. * 14 billion years * A television advertisement claiming that a product is light-years ahead of its time does not make sense because _________. * it uses "light-years" to talk about time, but a light-year is a unit of distance * The term observable universe refers to _________. * that portion of the universe that we can see in principle, given the current age of the universe * On a scale in which the distance from Earth to the Sun is about 15 meters, the distance from Earth to the Moon is _________. * small enough to fit within your hand * On a scale where the Sun is about the size of a grapefruit and...
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...To explain the photoelectric effect, Einstein came up with the photon hypothesis. The energy of a photon is associated with its frequency with the relation (1.1) Where h is the Planck constant. And to solve the paradox that electrons goes around the nuclear without electromagnetic radiation, Bohr put forward the atom model. In this theory the electrons have stationary orbits (1.2) Where is called the reduced mass. When the electrons transit from the high energy levels to the lower ones, the energy of the photons emitted is just the energy difference between two levels. In terms of the wavenumber 1.2 The Pickering Series and the Hydrogen-like Ions In our textbook the Modern Atomic and Nuclear Physics by Fujia Yang it talked about the hydrogen-like ions. And the first well-researched hydrogen-like atom is the helium ions, and this ion...
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...can be tested by experiment, it qualifies as a scientific hypothesis Prediction: Consequences that can be observed if the hypothesis is correct. The consequences should be absent if the hypothesis is not correct. Conclusion: Formulate the simplest general rule that organizes the hypothesis, predicted effects, and experimental findings. What is the principle of falsifiability? For a hypothesis to be considered scientific it must be testable?it must, in principle, be capable of being proven wrong. Fact: A phenomenon about which competent observers can agree. Theory: A synthesis of a large body of information that encompasses well-tested hypotheses about certain aspects of the natural world. Law: A general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted. Also known as a principle. Evidence: which serves to either support or counter a scientific theory or hypothesis. Experiment: is a test carried out in order to discover whether a theory is correct or what the results of a particular course of action would be . What did Galileo do to challenge Aristotle?s belief that heavy objects fall faster than lighter objects? Galileo very carefully examined Aristotle?s hypothesis. Then he...
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...day. You must ask yourself the question of how a particle so heavy in mass, a particle that can influence whole galaxies in the way they spin and their positioning in the universe, is still yet to be detected? This is down to the fact it doesn’t interact with light at all, it is literally ‘invisible’. Dark matter is the building blocks of the universe, without it, star systems like the Milky Way would cease to exist. Dark matter is an invisible mass that has such a large gravitational pull it can affect the speeds of entire galaxies in a cluster. The majority of the mass from a galaxy is actually considered to be dark matter. For example, “The Coma Cluster of Galaxies” is always moving at extreme rotational speeds. However, we can measure the mass of these galaxies by measuring the speed at which they travel and after the measurement it is obvious there is far too much mass to account for the amount of gas and planets in that cluster therefore, you must conclude that there is something else there making it so heavy. It appears there is actually about ten times as much dark matter in this cluster than there is...
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...island of stars in space, having from a few hundred million to a trillion or more stars * Milky Way Galaxy contains more than 100 billion stars; our Milky Way is in the Local Group * Galaxy cluster: collection of galaxies bound together by gravity. Small collections (up to a few dozen) are generally called groups, while larger collections are called clusters * Supercluster: gigantic region of space where many individual galaxies and many groups and clusters of galaxies are packed more closely together than elsewhere in the universe * Universe (cosmos): the sum total of all mater and energy * Observable Universe: the portion of the entire universe that can be seen from Earth * Universe is expanding, Big Bang occurred 14 billion years ago * Planet: moderately sized object that orbits a star and shines primarily by reflecting light from its star; an object is a planet if it (1) orbits a star, (2) is large enough for its own gravity to make it round, and (3) has cleared most other objects from its orbital path * Dwarf planet: object that meets the first two criteria but not the third, like Pluto * Moon (or satellite): an object that orbits a planet * Asteroid: a relatively small and rocky object that orbits a star * Comet: a relatively small and ice-rich object that orbits a star * Small solar system body: an asteroid, comet, or other object that orbits a star but is too small to qualify as a planet or dwarf planet * Star system: a...
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...Topic: Waves 1. What is a wave? A wave is vibration that travels and all waves are created by something vibrating. Waves transport energy but do not transport mass. 2. Describe the following terms associated with waves: a. amplitude height of wave b. wavelength length of a wave c. frequency number of waves per second (Hz) d. period how long a wave lasts when it arrives at a fixed point (measured in seconds) 3. What are radio waves? An electromagnetic wave of a frequency used for long distant communication. 4. Explain the difference between a transverse wave and a longitudinal wave, and give examples of each. In a longitudinal wave, the vibration travels in the same direction that wave travels. Examples of longitudinal waves include: Sound, p-waves (earthquakes) In a transverse wave, the vibration direction is perpendicular to direction that wave travels. Examples include: Light/electromagnetic, (radio, microwave, xray, etc.), water waves, swaves (earthquakes). The major difference between longitudinal and transverse waves is their direction. Longitudinal waves move left to right while transverse waves move up and down. 5. Compare and contrast: light waves vs. sound waves Light waves are transverse and sound waves are longitudinal. Light waves can travel through a vacuum but sound waves cannot. Speed of light is nearly 300 million m/s while sound has a speed of about 340 m/s. 6. What changes the pitch of sound...
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