Sumário
- Preface
1Science and the Universe: A Brief Tour
2Observing the Sky: The Birth of Astronomy
7Other Worlds: An Introduction to the Solar System
13Comets and Asteroids: Debris of the Solar System
14Cosmic Samples and the Origin of the Solar System
18The Stars: A Celestial Census
20Between the Stars: Gas and Dust in Space
21The Birth of Stars and the Discovery of Planets outside the Solar System
27Active Galaxies, Quasars, and Supermassive Black Holes
- AHow to Study for an Introductory Astronomy Class
- BAstronomy Websites, Images, and Apps
- CScientific Notation
- DUnits Used in Science
- ESome Useful Constants for Astronomy
- FPhysical and Orbital Data for the Planets
- GSelected Moons of the Planets
- HFuture Total Eclipses
- IThe Nearest Stars, Brown Dwarfs, and White Dwarfs
- JThe Brightest Twenty Stars
- KThe Chemical Elements
- LThe Constellations
- MStar Chart and Sky Event Resources
- Index
Thinking Ahead
Chapter Outline
Everything we know about stars—how they are born, what they are made of, how far away they are, how long they live, and how they will die—we learn by decoding the messages contained in the light and radiation that reaches Earth. What questions should we ask, and how do we find the answers?
We can begin our voyage to the stars by looking at the night sky. It is obvious that stars do not all appear equally bright, nor are they all the same color. To understand the stars, we must first determine their basic properties, such as what their temperatures are, how much material they contain (their masses), and how much energy they produce. Since our Sun is a star, of course the same techniques, including spectroscopy, used to study the Sun can be used to find out what stars are like. As we learn more about the stars, we will use these characteristics to begin assembling clues to the main problems we are interested in solving: How do stars form? How long do they survive? What is their ultimate fate?