This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis is an unformatted preview. Sign up to view the full document.
View Full DocumentReading Review Chapter 11 Basic Skills/ Definitions Quiz What is the approximate chemical composition (by mass) with which all stars are born?- Three quarters hydrogen, one quarter helium, no more than 2% heavier elements. The total amount of power (in watts, for example) that a star radiates into space is called its Luminosity. For example, the luminosity of the Sun is 3.7 x 10 to the 26 th watts. According to the universe square law of light, how will the apparent brightness of an object change if its distance to us doubles? Its apparent brightness will decrease by a factor of 4. Assuming that we can always measure the apparent brightness of a star, what does the inverse square law for light allow us to do? It allows us to calculate a stars luminosity if we know its distance, or calculate its distance if we know its luminosity. If star A is closer to us than star B, then Star As parallax angle is: Larger than that of star B. A larger parallax angle means the star is closer. Ten parsecs is about: 32.6 light-years If star A has an apparent magnitude of 3 and star B has an apparent magnitude of 5, which star is brighter in our sky? Star A. The magnitude scale is backward so that smaller numbers mean greater apparent brightness. From hottest to coolest, the order of the spectral types of stars is: OBAFGKM Our Sun is a star of spectral type: G Astronomers can measure a stars mass in only certain cases. Which one of the following cases might allow astronomers to measure a stars mass? The star is a member of a binary star system. If we can measure the orbital properties of a star around its companion, then we can measure the mass with Newtons version of Keplers third law. Which of the following terms is given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts? Spectroscopic binary The axes on a Hertzsprug- Russel diagram represent: Luminosity and surface temperature What can we infer, at least roughly, from a stars luminosity class?... View Full Document
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentChapter 9 Homework
Star Gazer chp 12
Reading Review Chapter 15
Study Guide for Exam 3
Chapter 18
Vocabulary in Content
Chapter 8 (The Family of Stars) Quiz
Chapter 15
Chapter 11 Review Questions
Spectroscopic Parallax
ASTR100 October 28
Chapter 17 True False Results
Copyright © 2015. Course Hero, Inc.
Course Hero is not sponsored or endorsed by any college or university.