misc:description | Pulsating variables are stars showing periodic expansion and contraction of their surface layers. The pulsations may be radial or nonradial. A radially pulsating star remains spherical in shape, while in the case of nonradial pulsations the star's shape periodically deviates from a sphere, and even neighboring zones of its surface may have opposite pulsation phases.
Depending on the period value, on the mass and evolutionary status of the star, and on the scale of pulsational phenomena, different types of pulsating variables may be distinguished. |