CCFs for Kepler-1649 c with low-S/N pixel masking. Two CCFs are shown: the standard one, and one where the stellar, planetary, and telluric contributions are shifted independently. In the shifted case, the feature follows the telluric-noise contribution at 53 km s⁻¹, as discussed in Appendix A. For illustration, we display the standard-deviation curve from the unshifted case, which shows a pronounced uncertainty peak at 0 km s⁻¹. This supports the interpretation that the feature is caused by noisy pixels associated with telluric absorption bands.