Learning Objectives By the end of this section, you will be able to: Is light actually bent from its straight-line path by the mass of Earth? How can light, which has no mass, be affected by gravity? Einstein preferred to think that…
Learning Objectives By the end of this section, you will be able to: Most stars end their lives as white dwarfs or neutron stars. When a very massive star collapses at the end of its life, however, not even the mutual repulsion…
Figure 24.1 Stellar Mass Black Hole. On the left, a visible-light image shows a region of the sky in the constellation of Cygnus; the red box marks the position of the X-ray source Cygnus X-1. It is an example of a black hole created…
The Death of Low-Mass Stars During the course of their evolution, stars shed their outer layers and lose a significant fraction of their initial mass. Stars with masses of 8 MSun or less can lose enough mass to become white dwarfs, which…
Learning Objectives By the end of this section, you will be able to: Everybody loves a good mystery, and astronomers are no exception. The mystery we will discuss in this section was first discovered in the mid-1960s, not via astronomical…
Learning Objectives By the end of this section, you will be able to: The discussion of the life stories of stars presented so far has suffered from a bias—what we might call “single-star chauvinism.” Because the human race developed around…
Learning Objectives By the end of this section, you will be able to: After a type II supernova explosion fades away, all that is left behind is either a neutron star or something even more strange, a black hole. We will describe the…
Learning Objectives By the end of this section, you will be able to: Supernovae were discovered long before astronomers realized that these spectacular cataclysms mark the death of stars (see Making Connections: Supernovae in History). The word nova means “new” in Latin; before…
Learning Objectives By the end of this section, you will be able to: Thanks to mass loss, then, stars with starting masses of at least 8 MSun (and perhaps even more) probably end their lives as white dwarfs. But we know stars…
Learning Objectives By the end of this section, you will be able to: Let’s begin with those stars whose final mass just before death is less than about 1.4 times the mass of the Sun (MSun). (We will explain why…