Observations of Pulsating Stars

Pulsations discussed will begin at the “top” of the instability strip with pulsating red giants and Miras, which are evolved stars nearing their own demise. The next discussed will be the Cepheids, both the “Classical” ones as well as the W Virginis (Population II stars). While moving down the instability strip of the HR Diagram, the next major type of variable (pulsating) star are the RR Lyrae stars, moving along the horizontal branch. After discussing the major types of radial pulsations seen on the instability strip, I will discuss a few other types of pulsating stars. The first will be the β Cephei stars (not to be confused with the Cepheids. These are hot, short period and small amplitude variables found near the upper part of the main sequence for spectral type B. Then, I will discuss the pulsations that are inherent with the supergiants. Supergiants are nearing the end of their life, and their behavior in their atmosphere is stochastic with the best observations. Finally, I will discuss an even more extreme example of pulsations, that of the luminous blue