The Milky Way and Beyond (2 page)
Read The Milky Way and Beyond Online
Authors: Britannica Educational Publishing
Subsequent Development on the Main Sequence
Origin of the Chemical Elements
The Most Abundant Chemical Elements
Notable Stars and Star Clusters
Advances Brought by Photography and Spectroscopy
Chemical Composition and Physical Processes
Chemical Composition of H II Regions
The Distances of Planetary Nebulae
Evolution of Planetary Nebulae
The Nature of the Progenitor Stars
Historical Survey of the Study of Galaxies
The Problem of the Magellanic Clouds
The Scale of the Milky Way Galaxy
Hubble's Discovery of Extragalactic Objects
The Distance to the Andromeda Nebula
The Golden Age of Extragalactic Astronomy
Principal Schemes of Classification
Other Classification Schemes and Galaxy Types
The Extragalactic Distance Scale
Physical Properties of External Galaxies
Interactions Between Cluster Members
Clusters of Galaxies as Radio and X-ray Sources
Notable Galaxies and Galaxy Clusters
