What Drives the Variability in Luminous Blue Variables
Faculty Mentor Name
Noel Richardson
Format Preference
Poster
Abstract
Luminous blue variable stars (LBVs) are evolved massive stars with strong winds and large variability. The cause of the variability of these stars is not yet understood. We used photometric data from TESS to study 30 LBV candidates in the Large Magellanic Cloud. The light curves extracted from TESS were compared to ASAS-SN light curves of the same star to rule out any instrumental errors with TESS. We then performed Fourier transforms on the corrected TESS data using Period04, allowing us to find the characteristic time scales of the variability. Using a non-linear fitting routine, we then measure the properties of the Fourier transform. From these parameters, we intend to explore how stellar characteristics, such as luminosity, 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 will also be using spectra from the 30 original LBVs plus 9 Galactic LBVs to look at their wind strengths, wind speeds, and radial velocities. Adding the Galactic LBVs will help us determine if the driving mechanisms for variability in LBVs change based on metallicity.
What Drives the Variability in Luminous Blue Variables
Luminous blue variable stars (LBVs) are evolved massive stars with strong winds and large variability. The cause of the variability of these stars is not yet understood. We used photometric data from TESS to study 30 LBV candidates in the Large Magellanic Cloud. The light curves extracted from TESS were compared to ASAS-SN light curves of the same star to rule out any instrumental errors with TESS. We then performed Fourier transforms on the corrected TESS data using Period04, allowing us to find the characteristic time scales of the variability. Using a non-linear fitting routine, we then measure the properties of the Fourier transform. From these parameters, we intend to explore how stellar characteristics, such as luminosity, 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 will also be using spectra from the 30 original LBVs plus 9 Galactic LBVs to look at their wind strengths, wind speeds, and radial velocities. Adding the Galactic LBVs will help us determine if the driving mechanisms for variability in LBVs change based on metallicity.