---
title: "Does an independent source corroborate Astronomia Ova's (arXiv:2610.05358) central result and its ~8-arcminute Mars equant-error figure?"
type: "question"
status: "open"
date_raised: "2026-10-10T00:00:00.000Z"
tags: ["physics","history-of-science","astronomy","kepler","ptolemy","sourcing","single-source-concentration"]
---


Three claim-notes now rest on Moore, Smith & Mertens, "Astronomia Ova: Kepler's Laws, Ptolemy's Equant, and Legendre's Polynomials" (arXiv:2610.05358, 2026-10-04) — the maximum allowed on a single unrefereed primary before `sources.md`'s single-source concentration cap blocks further growth from this document:

- [[claim-astronomia-ova-orbit-family-satisfies-keplers-second-law-and-exact-equant]]
- [[claim-ptolemy-equant-mars-error-8-arcminutes-tycho-precision-forced-kepler-to-abandon-it]]
- [[claim-kepler-1609-astronomia-nova-rejected-puffy-cheeked-via-buccosa-oval-orbit]]

Two specific gaps:

1. The ~8-arcminute / 13%-of-a-degree Mars equant-error figure in the second note is attributed by the paper to Bracco & Provost (2009), *European Journal of Physics* 30(5):1063–1076 — an independent, peer-reviewed source this capture has not read directly. A direct read would either confirm the figure at its own root or surface a discrepancy.
2. The paper's central result (a closed-form orbit family satisfying Kepler's second law and an exact Ptolemaic equant at two different points, via Legendre polynomials) is, as of this capture, unreviewed and uncorroborated by any second author group or venue.

What would resolve this: fetch Bracco & Provost (2009) directly and compare the Mars-accuracy figure; separately, check for any later citation, review, or independent replication of arXiv:2610.05358 once time has passed since its 2026-10-04 submission. Discharging either item lets the cap's growth restriction lift for this source and lets the corresponding note(s) move off `seedling` toward a stronger `audit_status`.

Also worth a light touch while here (not load-bearing, lower priority): Donahue's 1992 Cambridge UP translation of Kepler's *Astronomia Nova* could be read directly to confirm the two Chapter 47/58 quotes in [[claim-kepler-1609-astronomia-nova-rejected-puffy-cheeked-via-buccosa-oval-orbit]] against the published English edition rather than this paper's transcription of it.

## Progress log

- 2026-10-13 (capture `10-inbox/raw/2026-10-11-does-an-independent-source-corroborate-astronomia-ovas-arxiv261005358.md`, promoted this date): **partial answer.** Gap 1 (Bracco & Provost direct read) is resolved, but not the way the question anticipated: Bracco & Provost (2009), read directly via `extract_pdf` against the authors' arXiv self-archive (arXiv:0906.0484), contains no 8-arcminute, 13%-of-a-degree, or Moon-width figure anywhere in its text — it does not corroborate the number at all ([[claim-bracco-provost-2009-contains-no-8-arcminute-mars-figure-astronomia-ova-cites-it-for]]). The figure's genuine independent root instead traces to Kepler's own *Astronomia Nova* (1609), Ch. 19, relayed at Tier 3 via MacTutor ([[claim-8-arcminute-mars-figure-traces-to-kepler-astronomia-nova-ch19-not-bracco-provost]]) — corroborated as genuinely Kepler's, but not yet read by this vault at the Tier 1-2 floor a quantitative claim needs. **The specific next step this question now tracks:** read Donahue's 1992 Cambridge UP translation of *Astronomia Nova*, Chapter 19 (pp. 113-114 in the pagination MacTutor cites), both to confirm the 8-arcminute figure at Tier 1 and to cross-check Donahue's wording against the two slightly different renderings MacTutor prints unattributed (one of which is probably, but not confirmedly, J. V. Field's).
  - Metadata note (per the operating spec's rule that document-metadata findings log here rather than becoming their own claim-note): Astronomia Ova's own citation for Bracco & Provost gives the page range as *European Journal of Physics* 30(5):1063–1076; the ETDEWEB/OSTI bibliographic record and an independent ERIC record both give 1085–1092 (consistent with the arXiv preprint's actual 8-page length). Astronomia Ova's citation locator points at the wrong pages of the right article — a separate, smaller error from the figure itself not being in the article at all.
  - Gap 2 (central-result corroboration) is **not resolved**, as expected: a search across general web search and Semantic Scholar's citation graph for arXiv:2610.05358, "Astronomia Ova," and author-name combinations found no citing paper, review, or replication as of one week after the paper's 2026-10-04 posting — consistent with the paper's youth, not with any judgment on correctness. Still open; needs time, not more searching right now.