Pulsating Variable Stars

Pulsating Variable Stars Overview History of discovery What are pulsating variable stars? Why are they important? Any recent works?

Pulsating Variable Stars History 1595 – David Fabricius –o Ceti, 11 months 1784 – John Goodricke –d Cephei, 5d, 8h, 48min ~1912 – Henrietta Leavitt

Pulsating Variable Stars History

Pulsating Variable Stars PVS Physics Periodic luminosity changes Radial vs Nonradial Pressure wave estimation:

Pulsating Variable Stars PVS Physics

Classes:

Pulsating Variable Stars Who cares? Very large luminosities Distance calibrations

Pulsating Variable Stars Polaris! Period – , increase 4.5s/year – , brief hiatus Magnitude –Prior to 1963, 0.1mag –After 1966, sharp decline, 0.05mag Seems to no longer pulsate

Pulsating Variable Stars references References: – – – s/energyproduct/EnergyTransport/EnergyTransport.htm – – – –Polaris article: / html