A periodic flux model reduces eclipse scatter in four WASP-178 TESS sectors under a circular orbit
We test optical eclipses of WASP-178 b in all four public single-sector 120 s SPOC light curves returned by a saved MAST query. The sectors are 38, 65, 102, and 103, from 2021 to 2026. We use a fixed circular orbit, a uniform planet disk, signed depths, and local quadratic baselines. The 26 accepted events give a mean depth of 184.8 parts per million (ppm). The formal error is 26.7 ppm, but the error from event scatter is 89.0 ppm. We fit a periodic flux model outside both planetary transits and eclipses in each sector. It has eight harmonic pairs with a basis period near 0.739 day. Removing that model leaves the same events and weights. The mean becomes 183.4 ppm and the event error falls to 34.9 ppm, a reduction by a factor of 2.55. The conditional 95% event bootstrap interval is 120.3 to 246.6 ppm. Learning waveform coefficients on the other half of each sector gives 200.2 ppm with a 34.9 ppm event error. The 20 dependent control-phase depths after subtraction range from -70 to 46 ppm. The periodic model explains much of the event scatter while a positive eclipse-shaped signal remains in the tested fits. The intervals hold the learned waveform fixed and omit some correlated noise, geometry, and extraction errors. These tests do not establish a physical change from earlier custom photometry. We preserve the source FITS files, archive records, plan, code, result tables, figures, and reproduction instructions.
WASP-178 b · KELT-26 b · TESS · secondary eclipse · photometric contamination · correlated noise · reproducible astronomy
References
3- usesdoi:10.17909/t9-nmc8-f686
We use four public TESS SPOC 120 s light curves for TIC 160708862. The package preserves their exact archive identifiers and source bytes.
- usesdoi:10.1051/0004-6361/202346705
We adopt the Table 3 median clock and circular orbital geometry. The paper also identifies contamination and supplies the earlier TESS comparison. We do not use its extracted flux.
- Local fits give apparent decreases at eclipse and phase 0.75 in six WASP-121 b TESS sectors sci:sha256:adde673bfd380ffb8dc6e242a9d4dc231b7366ad6445edc9ef75bf6ed0536ad9
Its eclipse and control-phase results motivate control fits. Our target data and code are independent.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- usesFour TESS light curves do not resolve a change in the WASP-178 orbital flux wave under a block noise model
This study tests eclipse scatter in the same four light curves. We use its sector-specific doubled binary basis periods in a control. Our test concerns the orbital wave across visits and adds fixed pixel aperture controls. We do not reuse its code or extracted flux.
- usesFour TESS light curves do not resolve a change in the WASP-178 orbital flux wave under a block noise model
This study tests eclipse scatter in the same four light curves. We use its sector-specific doubled binary basis periods in a control. Our test concerns the orbital wave across visits and adds fixed pixel aperture controls. We do not reuse its code or extracted flux.
- usesFour TESS sectors give a 0.36953162-day binary clock near WASP-178 under a stable harmonic phase model
We use its selection of public TESS products, planet-event mask, and trend model as a starting point. This study adds a common harmonic clock, alias checks, held-out period-model scores, and a common-waveform test.