An Investigation into the Variability of Luminous Blue Variable Stars

Luminous blue variable stars (LBVs) are evolved massive stars with strong winds and large variability. The underlying mechanism driving the variability of these stars has not yet been determined. We used photometric data from TESS to study 30 LBVs (bona fide members and candidates) in the Large Magellanic Cloud. We performed Fourier transforms on the TESS data, allowing us to find the characteristic time scales and amplitudes of the variability. From these parameters, we are exploring how stellar characteristics, such as luminosity, color, and mass-loss properties correlate with properties of stellar variability. This can then be used to infer if internal gravity waves or stochastic processes such as subsurface convection drive the changes that we observe photometrically. We have also explored the TESS data for a small number of Galactic LBVs. While the Galactic light curves do not have the same duration as the sample from the LMC, these stars will help us determine if the driving mechanisms for variability in LBVs depends on the environment or metallicity.