Homework Problems Are Also You Study Guide

Exam 3 Study Guide. Homework problems are also you study guide.

Chapter 19

1. What is meant by the “period luminosity relation” of the Cepheid variables, and how can this be used as a distance indicator to the stars?

Chapter 22 2. Describe the evolution of a main-sequence star into a red giant or a supergiant. 3. Why are star clusters so useful for astronomers who want to study the evolution of stars? 4. Explain how you can determine the age of a star cluster from the H-R diagram of the star cluster.

Chapter 23 (skip 23.6) 5. Describe the steps in the formation of a white dwarf star and a planetary nebula beginning at the red giant stage. 6. Describe the properties of a white dwarf. What keeps the shape of a white dwarf star from the gravitational pressure? 7. Describe the nature and properties of a neutron star. 8. Describe the discovery and nature of pulsars. 9. What is degeneracy pressure? 10. Describe the evolution and deaths of the most massive stars, including Type II supernovae and supernova remnants 11. Discuss the main events in the occurrence of a Type Ia supernova

Chapter 24

12. What is meant by the terms “event horizon” and “Schwarzschild radius” and what is their relation to the mass of a black hole? 13. If the Sun could suddenly collapse to a black hole, how would the period of Earth’s revolution about it differ from what it is now? 14. A student becomes so excited by the whole idea of black holes that he decides to jump into one. It has a mass 10 times the mass of our Sun. What is the trip like for him? What is it like for the rest of the class, watching from afar?

Chapter 25 15. Draw two labeled sketches of the Milky Way Galaxy, one as seen from the side, and one as seen from the “top”; describe the structure and components of the galaxy. 16. How is the mass of the Milky Way measured, and how does this lead to the concept of dark matter? 17. Discuss the reason for the differences between population I and population II stars. 18. What is the observational evidence that something strange is happening in the nucleus of our Galaxy, and what is the probable explanation? Chapter 26 19. Compare and contrast elliptical galaxies and spiral galaxies. 20. Identify a galaxy by its shape, according to the Hubble sequence. 21. State in your own words what the Hubble’s law really says and what its implications are concerning the expansion of the universe. Learn how to calculate the receding speed of a galaxy using the Hubble’s law.

Chapter 27 22. Describe active galaxies, and the mechanisms proposed to explain their energy output and other characteristics. 23. Briefly relate the story of the discovery of quasars 24. Describe the current explanation of quasars and their energy sources. 25. What was the first evidence that quasars were different from astronomical objects before they were observed in visual wavelengths?

Chapter 28(Skip this chapter)

Chapter 29 26. Briefly describe the early history of the universe, starting from 10-43 second. 27. Compare the Big Bang with the Steady State theory and discuss the observational evidence for the Big Bang. 28. What is meant by “inflation”, and what problems does it solve in the Big Bang theory? 29. What is CMB? Briefly describe the story of the discovery of the microwave background radiation, including the roles of Gamow, Penzias and Wilson. 30. What is dark energy and what evidence do astronomers have that it is an important component of the universe? 31. What can we learn from the small fluctuations in the CMB?