The 2019–2024 TESS gaps of KIC 4544587 exceed the fixed ellipse limit for eccentricity 0.252 at inclination 87.9° if centers trace conjunctions
We test eccentricity 0.252 with public TESS eclipse times for KIC 4544587. Seven 120-second light curves from 2019 to 2024 give 156 centers and 62 complete primary-secondary-primary triples. The mean fractional gap increases from 0.667998 in 2019 to 0.674068 in 2024. The change is 19.14 minutes on a fixed period scale. An exact orbit calculation at inclination 87.9 degrees gives a maximum gap of 0.658811 for eccentricity 0.252. The 2024 mean is 48.09 minutes above this limit. If symmetric eclipse centers trace geometric conjunctions, no direction of that fixed ellipse can give these gaps. The 2024 gap sets an eccentricity lower limit of about 0.27684 at that inclination. Nine flux and timing settings change sector means by at most 6.88 seconds. An assumed error bound of 60 seconds per center still gives a lower limit above 0.2749 over inclinations from 85 to 90 degrees. This assumed bound is not a confidence interval. Pulsations and asymmetric light curves can bias physical centers. We do not establish a planet, an eccentricity change, or a new physical precession rate. The release preserves source FITS files, provenance, code, measurements, checks, and figures.
KIC 4544587 · TIC 120684604 · TESS · eclipsing binaries · eccentricity · eclipse timing · apsidal motion · reproducible research
References
5- usesdoi:10.17909/T9-NMC8-F686
The public TESS 2-minute collection supplies the seven unchanged SPOC light curves.
- usesdoi:10.1093/mnras/stt886
This source gives the prior eccentricity, inclination, period, and stellar pulsation context for KIC 4544587.
- challengesdoi:10.3847/1538-4357/ac22b0
Section 4.1 fixes eccentricity at 0.252. The later TESS gaps exceed its exact geometric maximum at inclination 87.9 degrees if measured centers trace conjunctions. This tests that parameter under stated assumptions, not the full tidal interpretation.
- usesdoi:10.1088/2041-8205/763/1/L2
The exact edge-on eclipse separation limit gives an established lower limit on eccentricity. We use its complementary maximum and a numerical finite-inclination extension.
- Symmetric profile fits reproduce the V1143 Cyg eclipse drift in 2019–2024 TESS data sci:sha256:7314d3e9fb684fefa04f22fb950122efe2e17ce1418366f3e244de725236ae85
This earlier study gives method context for symmetric profile fits, local eclipse triples, and timing controls in another binary. No source data or code from it enter this analysis.
Cited by
1 publicationPublic catalog entries on Sciscape.
- usesKIC 4544587 eclipse gaps from 2009–2024 fit an apsidal rate near 27 mrad/year if eccentricity is constant and centers trace conjunctions
We reuse seven unchanged TESS source files and their query and provenance records. We extend its TESS-only gap and rate tests with Kepler data, new timing fits, a short cadence check, and a timing bias test.