Study Guide for 3RD Astronomy Exam

Astronomy Assignment #5: Stellar Evolution Test Preparation

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This assignment is due on the day of the 2 nd exam

Submit this cover sheet with your assignment.

Complete the assigned problems from the text listed below and address the Instructor Assigned Topic. Mathematical problems may be hand written. Write out the problem, show your work in solving the problem and state your answer in a complete sentence. Failure to complete all three of these tasks will result in less than full credit awarded. The Instructor assigned topic must be typed.

Instructor assigned topic: After each of the items listed below in the Study Guid3e for the 2nd Astronomy Exam, do what the item states. That is, if the line says “Write” then write what is required. If the item says “Describe” then describe what is required. In other words, complete the study guide by filling in all the items a “successful student” should be able to do.

Study Guide for 2RD Astronomy Exam Fall 2015 The successful student will be able to: Write or identify the definition of the stellar motion term “Proper Motion” Describe or identify types of binary stars. State or identify what additional information can be obtained from and eclipsing binaries besides the combined mass of the stars. Properly label the axes of an HR diagram and identify the regions. Utilize the HR to identify a star’s luminosity, temperature, radius (and mass, if it is a main sequence star). Star Formation Describe the physical characteristics of a giant molecular cloud Identify the source of heating (energy production) in proto-stars Explain why more low-mass K & M main sequence stars form rather than the high-mass O & B stars. List the mass limits of stars and explain why these limits apply. Describe the processes and stages of star formation from a giant molecular cloud to an open cluster. Identify in a photograph the following objects: a GMC, Bok Globule, OB Association, HII region, Open Cluster Describe the t-Tauri wind. Interpret the physical changes of a forming star on an HR diagram. Identify and define the ZAMS line on an HR diagram. Describe the relationship between OB associations and HII regions. Main Sequence Stars List or identify the luminosity, mass, radius, temperature, and lifetime of an O main sequence star, the Sun and an M main sequence star. State the impact of convection in the envelope of very low mass stars on the stars main sequence lifetime. Describe or identify changes in a star during its main sequence lifetime. Giant Stars Describe how shell fusion in a star causes the star to become a giant star. Identify the “ashes” of H-burning and He-burning Mass loss and Death of Low-Mass Stars Match the stage of the Sun’s future evolution with the mechanism of energy production in that stage. Identify on an HR diagram the stage of the Sun’s evolution and its mechanism of energy production. List in chronological order the mechanisms of energy production in Sun-like stars. List in chronological order the stages of evolution in Sun-like stars. Describe the relation between the Helium Flash and the creation of a planetary nebula. Describe the components and characteristics of a planetary nebula. Identify the characteristics of white dwarf stellar remnants. Old age and Death of Massive Stars List the differences in energy production between low-mass stars and high-mass stars. Describe the interior structure of a high-mass star near the end of its lifetime. Identify the types of stars that will experience a core-collapse (Type II) supernova. Identify the composition of the core of a star about to experience a core-collapse (Type II) supernova. Describe two reasons why type II supernovas are very useful standard candles. Describe the impact of supernovas on the chemical evolution of the universe. Problems Use the Stefan-Boltzmann Law to determine the luminosity, radius or temperature of a star compared to the Sun. Determine the combined mass of a binary star system. Apply Wien’s Law to find the temperature of a star or its wavelength of maximum emission. Calculate the main sequence lifetime of a star.