Speaker
Description
The Transiting Exoplanet Survey Satellite (TESS) has accumulated an extensive photometric dataset for pulsating stars across the sky. Its scientific value for long-period pulsators depends strongly on the available time baseline. A single 27-day sector often covers only a fraction of a pulsation cycle, whereas stars in overlapping sectors may be monitored for several months, with coverage approaching one year in the continuous viewing zones (CVZs). Light curve quality also depends on target brightness, source crowding, and the ability to mitigate instrumental systematics.
Pulsators on the asymptotic giant branch (AGB) and beyond include semiregular variables (SRVs), OGLE small amplitude red giants (OSARGs), and RV Tauri stars in the post-AGB phase. These stars often exhibit irregular variability, with multiple pulsation modes contributing to the light curves of SRVs and OSARGs and alternating deep and shallow minima characterizing RV Tauri stars. Typical periods range from tens to several hundred days, and amplitudes vary from less than 0.1 mag to a few magnitudes.
We examine the available TESS data with particular attention to AGB stars in the Large Magellanic Cloud (LMC), which lies within the southern CVZ and therefore benefits from extended temporal coverage, while also presenting challenges due to severe crowding. Our study aims to provide a practical overview of the strengths and limitations of TESS observations for AGB variables and to identify promising targets and datasets for future studies of long-period stellar variability. Among the three types, we found SRVs to be the most promising targets for period analysis with TESS and therefore focus on these stars, comparing their TESS-derived periods with literature values.
Summary
variable stars - AGB - photometry - TESS