As the most favorable hosts for small transiting planets, M-dwarf stars can be very useful in detecting these objects. A newly accessible discovery space has recently opened up thanks to mid-to-late M-dwarfs characterized by sufficient TESS multisector coverage thanks to new Cycle 6+ observations. This paper presents a systematic transit survey of 121 ``newly enabled'' M3-M6 dwarfs (T_ eff =2700--3400, K) over a period of P=0. 5-100, d. These surveyed stars only recently crossed the multisector TESS detection threshold via Cycle 6+ coverage. The sample was selected from 498, 312 TIC M-dwarfs via a nine-step funnel. The pipeline combines a transit least squares approach (TLS) with a signal validation cascade, TRICERATOPS vetting, Gaia data release 3 (DR3) verification, and three empirical signal reliability tests. The pipeline validation achieved 100% recovery (16/16 planets) on ten known systems with zero false positives. The survey identified 20 transit-like signals across 16 systems, none of which had been characterized by any prior TESS object of interest (TOI) designations. The reliability framework classified two as tier 1 (high robustness), seven as tier 2 (moderate), and ten as tier 3 (noise-susceptible), while one monotransit was excluded. For nine out of 16 hosts, the candidate SDE sits at or below the measurable noise floor. Of the remaining seven, the floor lies below mathrm SDE _ ̊m inv =7 and the candidates end up exceeding it. The global false alarm rate is 17. 4% (21/121; Wilson 95% CI: 11. 6%, 25. 1%). The survey quantifies TLS sensitivity limits on active M3-M6 dwarfs with sparse TESS coverage. The two tier 1 candidates are priorities for RV confirmation. The ten tier 3 candidates require additional TESS sectors to establish a signal persistence, while nine systems call for high-resolution imaging to confirm their classification.
Yohann Tschudi (Fri,) studied this question.