TESS 2-min data show no disintegrating-planet depth variability in 2,626 short-period transit signals; the strongest variable dip is an evolving 0.377-day feature of a flaring M-dwarf pair

We searched TESS SPOC 2-minute light curves for transit-to-transit depth variability, the signature of dust tails from disintegrating rocky planets. We used 14,681 short-period (0.15-2 d) SPOC TCE signals on 11,410 stars and 32,896 light curves. For each signal, we measured a box depth with a local baseline at each orbit. We compared the scatter of these depths within each sector with the scatter at off-transit pseudo phases of the same star. The planet-like primary sample has 2,626 signals on 2,615 stars. Its depth-scatter ratio agrees with the pseudo-phase null. Nine signals are significant. Seven are bright giant-planet transits or eclipses with only 4-14 % depth jitter. The other two are stellar: a periodic stellar waveform (TIC 41233766) and an evolving 0.377-day dip of the unresolved M-dwarf pair TIC 148081648/148081650. That dip persists from 2019 to 2026. In 2023 its depth fell from 10.8 to 4.3 ppt after the largest flare of the sector, while the rest of the waveform stayed constant. This matches flare-related dip collapse in complex periodic variables, so we report the pair as a CPV-like candidate, not a planet. In 14,400 injections, KIC 12557548 b-like variability is recovered in 81 % of cases at per-transit S/N 2-4 and in 99 % at S/N 4-8. Constant depths give at most 0.4 % false flags. Thus fewer than 0.18 % (rms/mean about 0.8) and 0.30 % (rms/mean 0.5) of the primary-sample signals carry such variability (95 % confidence). The three known disintegrating planets with 2-minute data are too faint for an orbit-by-orbit test (per-transit S/N 0.33-0.38). Limits: only SPOC TCEs, within-sector variability, at most four sectors per star, and no spectra for the M-dwarf pair.

TESS · disintegrating planets · transit depth variability · threshold crossing events · injection-recovery · complex periodic variables · M dwarfs · stellar flares · null result · KIC 12557548 · K2-22 · KOI-2700 · TIC 148081648