In this lab, you will revisit the math skills you’ll need in your studies of astronomy. Astronomy 3 is not heavy on calculations, but several mathematical concepts (exponents, scientific notation, unit analysis, ratios, and proportionalities) will be used often in homework, labs, and exams.
Learning Objectives
Multiply and divide exponents
Express a number in scientific notation
Work with units of measure
Manipulate ratios and proportionalities
Lab 2: Naked-Eye Astronomy
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For centuries, humans have incorporated the night sky into their daily lives, admiring its beauty and using it to answer burning questions – including how to get home. The night sky and its stars are extremely helpful for orienting a lost traveler, and written accounts of stellar navigation go back thousands of years. Today, you will learn some of the tricks that humans have used for centuries to find their way, before the advent of compasses and GPS devices.
Learning Objectives
Lab 3: Light and Telescopes Lab
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As you heard in lecture, light plays a crucial role in astronomy. We use telescopes to capture light emitted by objects throughout the Universe. In this lab, you will study the ray behavior of light and the basics of telescopes. To isolate your experiments from ambient light, this lab will take place in a darkened room.
Learning Objectives
Decribe the ray behavior of light
Describe how light is affected by lenses
Describe how light is affected by mirrors
Describe how curved lenses and mirrors bring light to a focus
Draw and interpret ray diagrams for light
Explain the function of the two lenses in a simple telescope
Lab 4: Color and Spectra
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In this lab, you will conduct a number of experiments on the nature and behavior of light. As you heard in lecture, light plays a crucial role in astronomy. Because of the enormous distances in the Universe, our understanding of the Cosmos is based almost completely on light alone. To isolate your experiments from ambient light, this lab will take place in a darkened room.
Learning Objectives
Describe the difference between emission, absorption, transmisson and reflection/scattering.
Describe the composition of white light.
Describe the difference between continuous and emission line spectra.
Describe how colored light may be combined to make colors on a screen.
Describe the function of color filters.
Describe how to use spectroscopy to identify the composition of an unknown gas.
Lab 5: Gravity and Extrasolar Planets
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Way back in the 17th Century, Isaac Newton developed his universal law of gravitation, which you’ve heard about in lecture. Any two objects with mass anywhere in the Universe attract each other! When these objects are a star and a planet, the result is usually an orbit. Our scientific understanding of gravity has become so well refined during the past four centuries, that we can now use observations of moving objects to infer the presence of objects we cannot see directly. In today’s lab, we look at a hot topic in astronomy: the detection of planets around faraway stars.
Describe the conditions required for a set of objects to be in balance.
Define the center of mass and locate its position in a set of two objects.
Explain why stars wobble in the presence of a planet.
Interpret radial velocity curves for stars and measure the wobble period.
Apply Kepler’s Third Law to determine the orbital distance of a planet from its star.
Lab 6: Spectra, Stars, and the H-R Diagram
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Astronomers study the Universe by collecting light from distant stars. We measure starlight both from stars in our own galaxy and from the combined light of billions of stars in far away galaxies. The light from these stars provides the basis for much of our understanding of the Universe. In this lab, we will investigate some of the basic properties of stars and the insights provided by the Hertzsprung-Russell Diagram.
Understand how to interpret graphical representations of spectra; i.e., plots of intensity vs. wavelength
Explain how to measure the surface temperature of a star from its spectrum.
Use the H-R Diagram to draw inferences about the basic properties of stars.
Describe and apply the relationships between mass, radius, luminosity and surface temperature of a star.
Describe how the peak wavelength of a thermal spectrum changes with temperature.
Describe how the apparent brightness of a star changes with distance.
Lab 7: Structure and Motion of Spiral Galaxies
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The Sun and 200 billion of its closest stellar neighbors make up what we call the Milky Way galaxy, named for the white lane of light these stars create in Earth’s night sky. Astronomers estimate that about two-thirds of all galaxies in the Universe are spiral galaxies similar to the Milky Way, and from observing these galaxies we can learn about our own galactic environment and the Universe as a whole, including dark matter.
Learning Objectives
Identify and calculate the important quantities that describe circular motion.
Plot and interpret rotation curves for solid bodies, planetary systems, and spiral galaxies.
Describe the mass distribution of a system based on its rotation curve.
Explain how spiral galaxies provide evidence for the existence of dark matter.
Describe how the appearance of a spiral galaxy changes in different filters, and explain why.
Lab 8: Expansion of the Universe
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The fact that the Universe is expanding is one of the most amazing scientific discoveries of last century. But understanding the ramifications of this can be tricky. In this lab, you will investigate the concept of expansion and consider how we can determine the age of the Universe itself. In the process, you will tackle some of the most confusing concepts of our expanding Universe: what exactly is expanding? Expanding into what?
Learning Objectives
Describe the measurement of redshift for a galaxy.
Explain whether galaxy redshifts necessitate that we are at the center of the Universe.
Explain why an expanding universe would follow Hubble’s “law”
Describe how our understanding of the age of the Universe depends on acceleration of the expansion.
Explain why expansion implies a finite age for the Universe.
Determine the Hubble time from Hubble’s law and relate it to the age of the Universe.
Plot the expansion of the Universe and interpret plots to identify its age.