A Methodological Reassessment of Unvalidated Transit-Like Signals in TESS Photometry of the M-Dwarf TIC 60611369

Automated period-search algorithms and unvetted visual inspection are both susceptible to producing unvalidated transit-like claims from Transiting ExoplanetSurvey Satellite (TESS) photometry. In this methodological case study of the bright M-dwarf TIC 60611369(Tmag = 6.19, Teff ≈ 3100 K), we retract two claimsmade in earlier stages of this work: (1) a preliminaryinterpretation of a ∼10% flux deficit as an eclipsingbinary signature, which we now attribute to unvetted visual interpretation of ordinary photometric scatter, since Science Processing Operations Center (SPOC)data was used from the outset; and (2) a Box LeastSquares (BLS; Kov´acs et al. 2002) periodogram peak atP = 14.5222 days (depth 1.5213% ± 0.0013%) in Sector 10 Quick-Look Pipeline (QLP) data, which we hadprovisionally attributed to a spacecraft downlink datagap. Explicit epoch-to-gap mapping shows this attribution to be incorrect: the predicted transit windowdoes not overlap either identified gap. We instead findsubstantially stronger evidence against this signal fromtwo independent tests. First, a permutation-based falsealarm probability (FAP) test (10,000 flux-shuffled trials)shows that a periodogram peak with SDE ≥ 1.57 (ourmeasured value) arises in 100% of shuffled trials, i.e.the signal is not significant relative to the permutationbased null distribution constructed under this test. Second, a detrending-window sensitivity test shows the recovered period is unstable, ranging from P = 6.43 to15.77 days depending on the Savitzky–Golay windowlength (25%–100% of our fiducial window), indicatingthe nominal 14.52-day period is contingent on a specific preprocessing choice rather than a robust featureof the data. An injection–recovery test (56 synthetictransits, depths 0.5%–3.5%, periods 4–18 h) recoversonly 30/56 (53.6%) of injected signals overall. Thistest used sub-day periods and a fixed 0.3-day transitduration for computational convenience; we note explicitly that it characterizes short-period pipeline behavior only and does not probe the candidate’s own14.52-day period regime, and that the fixed durationexceeds the injected period itself at the shortest periods tested– a limitation we flag rather than a validated design (Section 5). For Sector 64 SPOC data,we report an RMS scatter of 216.6 ppm and a maximum BLS SDE of 4.42 at P = 1.0068 days; a permutation FAP test gives FAP = 72.3% for this peak, anda cross-check against centroid position (centroidcentroidrow) and background flux (sapcol,bkg) diagnostics finds no matching ∼1-day periodicity in any of thethree, so this specific instrumental-origin hypothesis isnot supported by the diagnostics we tested, and thepeak’s origin remains unidentified. We conclude thatthe currently available TESS data do not validate thetransit-like signals previously reported for this target;the Sector 10 signal in particular is statistically consistent with noise and does not survive a basic robustnesscheck against preprocessing choices. We do not claim tohave proven a non-astrophysical origin for either signalwith certainty, nor that the target hosts no transitingcompanion– our own injection–recovery results showthe adopted pipeline has substantial incompleteness atthe relevant depth and period range– but we find noevidence in the present data supporting either of ourearlier claims.