Velocity Curves and Pulsating Variables

Later we shall discuss pulsating variable stars. These stars exhibit a variation in light output and periodic Doppler shifts because of the pulsation of the surface. As we shall see shortly when we discuss eclipsing variables, a spectroscopic binary that is also an eclipsing binary exhibits periodic changes in light output and fluctuating red and blue Doppler shifts too. Thus, it is sometimes difficult to determine whether a variable is a pulsating variable or an eclipsing binary. Careful analysis of the light curve's details can often distinguish these two cases.