Journal. EPJ Web of Conferences
Abstract. Space photometric data of the Kepler Cepheid, V1154 Cygni, and those of SZ Tauri (MOST photometry) indicate that classical Cepheids are not strictly regular pulsators. Cycle-to-cycle period changes and variations in the shape of the light curve are revealed from the continuous photometry covering 6 cycles of SZ Tau pulsation and several hundred pulsation cycles of V1154 Cyg. To make the situation more interesting/complicated, the MOST light curve of RT Aurigae (a Cepheid pulsating in the fundamental mode) shows stellar oscillations in a highly repetitive manner.