Autoregressive moving average modelling of TESS photometry of massive stars

Abstract

Standard statistical time-series analysis methods developed for observations regularly spaced in time are applied to measurements of 30 massive stars. Two Transiting Exoplanets Survey Satellite orbits of observations of each of the stars are analysed using this time-domain methodology. It is found that the majority of light curves do not exhibit quasi-periodicities, i.e. the variability is fully aperiodic. The effective temperature and gravity can be used to predict with good accuracy the presence/absence of quasi-periodicities. Frequencies have a quadratic dependence on the effective temperature. The calculation of characteristic frequencies is also discussed. It is shown that the use of inappropriate spectral forms for this purpose may lead to biased results.