Contents
- 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
Key Terms
- elliptical galaxy
- a galaxy whose shape is an ellipse and that contains no conspicuous interstellar material
- Hubble constant
- a constant of proportionality in the law relating the velocities of remote galaxies to their distances
- Hubble’s law
- a rule that the radial velocities of remote galaxies are proportional to their distances from us
- irregular galaxy
- a galaxy without any clear symmetry or pattern; neither a spiral nor an elliptical galaxy
- mass-to-light ratio
- the ratio of the total mass of a galaxy to its total luminosity, usually expressed in units of solar mass and solar luminosity; the mass-to-light ratio gives a rough indication of the types of stars contained within a galaxy and whether or not substantial quantities of dark matter are present
- redshift
- when lines in the spectra are displaced toward longer wavelengths (toward the red end of the visible spectrum)
- spiral galaxy
- a flattened, rotating galaxy with pinwheel-like arms of interstellar material and young stars, winding out from its central bulge
- type Ia supernova
- a supernova formed by the explosion of a white dwarf in a binary system and reach a luminosity of about 4.5 × 109 LSun; can be used to determine distances to galaxies on a large scale