Paired flux fits show strong loss of a fixed heartbeat template in nine QLP sectors for KIC 3749404

We measure a fixed heartbeat template in nine public TESS Quick-Look Pipeline (QLP) light curves for KIC 3749404. The files cover 2019 to 2024. Paired fits use the same cadences, a 20.3067191-day template, and local quadratic baselines. Ten retained pulse windows give a mean coefficient of 3409 ppm in SAP_FLUX and 42 ppm in detrended flux. The ratio of the summed coefficients is 1.24%. Its conditional 95% paired block-wild interval is -3.33% to 5.09%. Four sectors also provide SYS_RM_FLUX. The corresponding ratio is 0.44%, with an interval of -2.29% to 2.99%. A separate template from Kepler quarters 8 to 10 gives 1.43% retention. Baseline, window, epoch, tidal mode, weighting, and noise-block checks give the same qualitative result. QLP is designed to remove stellar variability before a planet search. This study adds a target-specific measurement set and a reproducible paired audit. The statistic measures a template coefficient. It does not measure the full physical heartbeat amplitude or the response of QLP to an injected signal. Raw flux can contain instrumental signals. These data do not give a reliable new apsidal precession rate or evidence for a new companion. The package includes 12 unchanged source FITS files, source hashes and URLs, code, fit results, figures, and reproduction instructions.

TESS · Kepler · heartbeat binary · KIC 3749404 · TIC 137483608 · QLP · stellar variability · detrending · reproducible data audit