AAVSO: American Association of Variable Star Observers

High-precision Radial Velocity Measurements of Classical Cepheids (Abstract)

Volume 48 number 1 (2020)

Richard I. Anderson
ESO, Karl Schwarzschild Str. 2, Garching b. München 85748, Germany; randerso@eso.org


(Abstract only) I will review the surprising new insights into the nature of classical Cepheid variables that have been enabled by radial velocity measurements precise enough to measure the speed of a human walking. Following a brief overview of Cepheid properties, I will focus on two celebrities: first on the prototype, δ Cephei, and its secret companion that can only be detected indirectly, and then on α UMi (the North Star, Polaris), which is both the nearest Cepheid variable and whose detailed astrophysical explanation remains a mystery.