Periodic Analysis Of GW Ori Based On TESS Satellite Data

This paper mainly studied the light curve of the GW Ori system using high-precision photometric data from the TESS satellite.GW Ori is a young hierarchical triple system located in λ Orionis,consisting of a binary(GW Ori A and B),a tertiary star(GW Ori C)and a rare circumtriple disk.In the past,due to limited observation data and insufficient precision,several short-period signals have been detected in the system,but the results from different studies were not consistent.As one of the most successful transiting surveys,Transiting Exoplanet Survey Satellite(TESS)provides an unprecedented opportunity to make a comprehensive periodic analysis of GW Ori.TESS is a space telescope launched by NASA in 2018.Its main purpose is to provide users with high-precision stellar photometric data,which is of great scientific significance for studying the temporal astronomical information of stars.TESS provided nearly90 days of light curve data(divided into four parts)for GW Ori.Thanks to these high-precision light curves,we can conduct a comprehensive investigation of the short-period signals in this system.The first chapter of this paper we mainly introduces the research background and current status of GW Ori,as well as the physical scenarios corresponding to different light curves in young multiple systems.The second chapter introduces the observation parameters and data products of the TESS and the periodic analysis algorithm suitable for non-uniform time series.The third chapter introduces the preprocessing of the GW Ori light curve,including the selection of aperture masks and detrending.In four chapter,we discover two significant modulation signals by analyzing the light curves of GW Ori’s four observations in TESS,i.e.,3.02 ± 0.15 d and 1.92 ± 0.06 d,which are very likely to be the rotational periods caused by starspot modulation on the primary and secondary components,respectively.We calculate the inclinations of GW Ori A and B according to the two rotational periods.The results suggest that the rotational plane of GW Ori A and B and the orbital plane of the binary are almost coplanar.We also discuss the aperiodic features in the light curves;these may be related to unstable accretion.The light curves of GW Ori also include a third(possible)modulation signal with a period of 2.51 ± 0.09 d,but the third is neither quite stable nor statistically significant.