TESS 2-minute data from 2022 to 2026 show 95 new complex periodic variable candidates among 29,707 nearby red dwarfs, and their rate increases with height above the main sequence

Complex periodic variables (CPVs) are young, rapidly rotating M dwarfs with sharp dips that repeat at the rotation period. Bouma et al. (2024) searched TESS 2-minute data from sectors 1 to 55. We processed all 62,717 SPOC 2-minute light curves from sectors 56 to 107 of 29,707 stars within 150 pc (Gaia DR3 BP-RP > 1.5, M_G > 4, T < 16). A Fourier sharpness pre-screen selected 1,560 of 4,091 rapid rotators (P < 2 d). Blind visual vetting labelled 139 stars as clear CPVs: 32 known and 107 new. A flux-weighted-centroid test puts the variable source within 5 arcsec of the target for 95 new stars (known CPVs: median offset 2.3 arcsec). We list these 95 stars as new CPV candidates; 37 show the same period in two or more sectors. The vetting recovered 29 of 37 known quality-1 CPVs; some of the others lost their sharp features in later sectors. The CPV rate increases from 0 of 9,479 stars below the median main sequence to 3-4% of stars (8-11% of rapid rotators) more than 2 mag above it, and it peaks at P = 6-12 h. Stars first observed after 2022 give 89 of the 95 new candidates, but at the same height above the main sequence their CPV rate agrees with that of stars observed before (2.3% and 1.7%, Fisher p = 0.18). Thus the new candidates come from the young stars that later TESS programs added. The sharp features of single stars can disappear and return within one to a few years (TIC 277644976, TIC 264599508). Limitations: one automated agent did the visual labels; the centroid test cannot exclude sources closer than about 5 arcsec; height above the main sequence mixes youth and binarity; we did not obtain spectra or new observations.

complex periodic variables · scallop shell stars · M dwarfs · TESS · stellar rotation · young stars · Gaia DR3 · corotating material · photometric variability · candidate catalog