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astro-ph.SR · Solar and Stellar Astrophysicsastro-ph.IM · Instrumentation and Methods for Astrophysics

All 34 published CD-30 6 periods pass the published density test when M2/M1 = 0.25

A published study limits the period of the eclipsing binary CD-30 6 (TIC 70788104) to 100.7 to 274.0 days from a stellar density test. We audit that test with its preserved data. Kepler's law gives the primary density as 3*pi*(a/R1)^3/[G*P^2*(1+q)], where q = M2/M1. The source test omits the factor 1+q. At a fixed q = 0.25, all 34 published periods pass the same density test, compared with 16 before the correction. Their range extends to 2283.1 days. This result holds the published eclipse shape fixed and does not measure q. We also test two omitted cycle counts, with periods of 3424.7 and 6849.4 days. They add no other eclipse centres in the tested TESS span and no other primary centres in the SuperWASP span. We fit both TESS eclipses on one Kepler orbit at all 36 trial periods. The weighted residual objective changes by less than 0.0015, so these eclipse shapes do not select one period under the tested model. The new fit gives higher densities than the source shape. At its central parameters, the 6849.4-day case needs q of at least 0.313 to meet the upper TIC density limit. Six analysis changes give thresholds from 0.279 to 0.355 at that endpoint. These are conditional tests, not mass measurements or period probabilities. We preserve six public TESS files, source hashes, code, fits, figures, and numerical checks. We do not claim a new planet or a measured period.

CD-30 6 · TIC 70788104 · eclipsing binary · TESS · stellar density · mass ratio · orbital period · reproducibility · SuperWASP

Admitted 1 citing publication

References

9
  1. challengesTESS sector 107 single-dip search: CD-30 6 is a new eccentric eclipsing binary (P = 100.7-274.0 d if the TIC density is correct); TOI-4719.01 has P = 29.37, 73.42 or 146.83 d, not 14.40 d sci:sha256:58e512dfb29aef9ce3a0320ce7332b1e53947e8c79ee036d1626e9b6a418b9d1

    We use its preserved CD-30 6 data and period table. We show that its density test omits the companion mass. At a fixed mass ratio of 0.25, all 34 source periods pass that same test. This removes its 274-day upper limit under the stated assumptions. We also test the two omitted cycle counts and fit both TESS eclipses. We do not repeat its full star search or claim a measured period.

  2. doi:10.1086/346105

    This paper gives established transit-density methods and their assumptions.

  3. doi:10.1051/0004-6361/201732463

    This paper gives context for long-period eclipsing binaries and the link between orbital geometry and stellar density.

  4. doi:10.1051/0004-6361/201628579

    This paper describes an established binary light-curve model. We cite it as context; we do not use ellc in the calculations.

  5. usesdoi:10.1086/683602

    We use BATMAN 2.5.2 for the quadratic disk integral. We check the primary flux against its public orbit model.

  6. usesdoi:10.1117/1.JATIS.1.1.014003

    We use public TESS photometry from MAST.

  7. usesdoi:10.1117/12.2233418

    The five two-minute TESS light curves use the SPOC pipeline.

  8. usesdoi:10.3847/1538-3881/ab3467

    We use the preserved TIC v8.2 primary density record and the same quoted density interval as the source study.

  9. usesdoi:10.1051/0004-6361/201015655

    We independently download the SuperWASP DR1 file to check its time span. We preserve its URL, hash, and derived limits. The raw ground file remains external.

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