TESS fits show increased central pulse amplitude relative to the second orbit harmonic of HD 74423 from 2019 to 2025
We fit 200,515 public TESS exposures of HD 74423 in 12 sectors from 2019 to 2025. Each sector has a separate pulse frequency and phase. An exploratory comparison shows an increase in the ratio of central pulse semi-amplitude to semi-amplitude at twice the orbit frequency. Its mean with equal weight for each sector increases from 0.084541 in 2019 to 0.095361 in 2025, a rise of 12.80%. A conditional 95% interval is 12.20% to 13.40%. The SAP flux check gives a 12.75% rise. A comparison on the same camera and CCD gives a 12.51% rise. The first question, chosen before flux inspection, tested the first side peaks relative to the central pulse peak. That ratio has no clear change: the 2025 minus 2019 mean is 0.000374, with a conditional 95% interval of -0.007096 to 0.007930. Residual multipliers in time blocks give these intervals under the fitted model. The exploratory choice and calibration errors are outside these intervals. The data show a change in relative pulse strength, but they do not identify its physical cause. The package includes original FITS files, source records and hashes, the analysis plan, code, fit tables, covariance matrices, numerical checks, figures, and repeat instructions.
HD 74423 · TIC 355151781 · TESS · stellar pulsation · binary stars · amplitude variation · tidally tilted pulsators · reproducible analysis
References
3- usesdoi:10.1038/s41550-020-1035-1
This study uses the published orbit and pulse reference frequencies and extends the 2019 observing scope.
- doi:10.1093/mnras/staa2376
This paper gives a physical framework for tidal effects on stellar pulses. The present analysis tests observed amplitude ratios without fitting that theory.
- usesdoi:10.17909/T9-NMC8-F686
This collection supplies all 12 public SPOC light curves. Exact file names, retrieval times, and hashes are preserved.
Cited by
4 publicationsPublic catalog entries on Sciscape.
- TESS fits with fixed orbit spacing do not resolve a 2019–2024 pulse sideband ratio change in TIC 63328020
This related SCI study tests pulse ratios in HD 74423. The present work tests a different ratio in TIC 63328020. No source code or data from that study were reused.
- usesA TESS model gives a conditional 95% upper bound of 3.1% on HD 74423's mean pulse pattern change from 2019 to 2025
We reuse its public TESS files, source fitting code, per-sector coefficients, and block-score covariance matrices. We extend its amplitude-ratio test to the full complex main-pulse pattern and rebuild the first and last sector fits from the original inputs.
- usesHD 74423's second harmonic does not match a scaled square of its main pulse envelope in 12 TESS sectors
We reuse its 12 preserved public TESS files, provenance records, and parts of its sector fit code. We extend the second harmonic range and test a different relation.
- TESS fits show higher strengths of modes 2 and 4 relative to mode 1 in CO Cam in 2024 than in 2019
This report uses amplitude ratios to reduce effects of a common flux scale for HD 74423. The present work tests ratios between pulse modes in CO Cam with new code.