Searching for high-amplitude gamma Doradus variables in the Gaia and the TESS missions

The gamma Doradus variables are A- and F-type pulsating stars located in the classical instability strip in the Hertzsprung-Russell Diagram, close to the main sequence. They are characterized by high order, low degree non-radial gravity (g) mode pulsations. Their pulsation periods range from 0.3 to 3 days, and their pulsation amplitudes typically do not exceed 0.1 magnitude in the V-band. However, several stars have been discovered with unusually high amplitude variability, reaching as high as 0.3 magnitude. When the physical properties of these high-amplitude gamma Doradus (HAGDOR) stars are compared with those of the low-amplitude stars, they do not appear to be different. To investigate this question in more detail and on a much larger sample, we selected the potential gamma Doradus stars in the Gaia Data Release 3 variability catalog and used the ultra-precise space photometry of the TESS mission to study them. We collected the full-frame image light curves that are prepared with the MIT Quick Look Pipeline and are available for stars brighter than 13.5 magnitude in TESS bandpass, and searched for members of the HAGDOR group by both visual inspection of the light curves and with Fourier analysis. These two groups of stars were then compared based on different physical properties adopted from the Gaia mission.