Exploring ER UMa-type Dwarf Novae using Photometry Data of Transiting Exoplanet Survey Satellite (TESS)

An investigation was conducted into eleven ER Ursae Majoris (ER-UMa) star systems using photometric light curve data obtained from the Transiting Exoplanet Survey Satellite (TESS), with a focus on exploring their mass ratios, superoutburst characteristics, and superhump dynamics. This research marks the first instance where all ER Ursae Majoris-type dwarf novae observed by TESS were investigated simultaneously. In this study, we determined the A, B, and C stages of the superhumps in the superoutbursts of each ER-UMa system using the O-C method, and we derived the mean superhump periods as well as the superhump periods in each of the A, B, and C stages. Employing the stage A superhump periods, we estimated the mass ratios (M2/M1) between the white dwarf primary (M1) and the red dwarf secondary (M2) in each system. In addition to the TESS data, we utilised photometric light curve data from the American Association of Variable Star Observers (AAVSO), Zwicky Transient Facility (ZTF), and the All-Sky Automated Survey for Supernovae (ASAS-SN) project to determine variations in supercycle periods and the recurrence periods of normal outbursts for each ER-UMa system.