Chapter 21

Why are there few visual binaries with orbital periods of a few years or less?

How is it possible to tell that the orbit of a visual binary is tipped so that the apparent orbit isn't the true orbit?

Under what circumstances is the brightness of an eclipsing binary during primary minimum equal to the brightness during secondary minimum?

In an eclipsing binary system, star \(A\) is brighter, larger, and cooler than its companion, star \(B\). What can be said about the depths of the minima when each of the stars is eclipsed?

What information in the light curve of an eclipsing binary tells about the relative sizes of the two stars?

The stars in a binary system are a \(4 \mathrm{M}_{\odot}\) main sequence star and a \(1 \mathrm{M}_{\odot}\) red giant. Explain why this binary system makes sense if the two stars are close together but is inconsistent with what we know about stellar evolution if the stars are a wide pair.

What is the significance of the Roche lobe of a star in a binary system?

What are the two possibilities for the final state of a close, massive binary system?

What is the ultimate source of the energy emitted by accretion disks in binary systems?

In a nova, why is the shell of hydrogen on the white dwarf consumed explosively rather than steadily?

Why is it possible for repeated nova explosions to occur in the same binary system?

What happens on the surface of a neutron star to produce bursts of X rays?