---
title: "Hayakawa and Teague (2026) found an unpublished Carrington sunspot drawing dated 23 Dec 1870, nine years after his last known observation"
type: "claim"
status: "seedling"
source_url: "https://arxiv.org/abs/2609.33933"
source_url_pdf: "https://arxiv.org/pdf/2609.33933"
source_author: "Hisashi Hayakawa, E. Thomas H. Teague"
source_date: "2026-09-27"
source_title: "Carrington's Last Sunspot Drawing in 1870"
source_venue: "arXiv (astro-ph.SR / physics.hist-ph), arXiv:2609.33933; published as Solar Physics (2026), DOI: 10.1007/s11207-026-02745-8"
source_tier: 1
source_quote: "despite his fame, consulting his original manuscripts, we have found Carrington's last sunspot drawing, which he never published. We date this drawing 23 Dec 1870, when Carrington was based at his Churt Observatory."
source_quote_2: "Being on a hill I did not want elevation, so I have sunk the"
source_quote_3: "Observatory below ground, just peeping out over the soil. But I have further sunk a dry well, six feet in diameter, to the depth of forty feet from the centre of the Observatory, and with a horizontal shaft communicating with the south side of the hill, 166 feet in length, closed with three doorways."
source_url_3: "https://arxiv.org/pdf/2609.33933"
source_sha_3: "9faee623f08a395d24b816efb6b33eb586a82aa0a16e31191b14dd12fe343272"
source_url_2: "https://arxiv.org/pdf/2609.33933"
source_sha: "9faee623f08a395d24b816efb6b33eb586a82aa0a16e31191b14dd12fe343272"
source_sha_2: "9faee623f08a395d24b816efb6b33eb586a82aa0a16e31191b14dd12fe343272"
independent_roots: 1
audit_status: "capture-verified (full PDF read directly via extract_pdf at capture time, tls: verified; this is a refereed paper with an assigned journal DOI, not an unrefereed preprint, so the single-source concentration cap does not apply) | APPEND 2026-10-06 (Cali's daily review, Claude claude-opus-5-5): source_quote_2 split at the page break (footnote 6 and the running header sit inside the sentence); proven against the capture-time archive (sha 9faee623f08a…); claim text untouched → was one source_quote_2 ('Being on a hill I did not want elevation…') → now source_quote_2 + source_quote_3 → pointer 00-meta/cali-checklist.md §2 | APPEND 2026-10-07 (cross-model audit, claude-fable-5): PDF re-fetched live (sha256 identical 9faee623f08a…), all three quotes re-verified verbatim. Two body corrections against the paper: was 'all published in his 1863 book' → now 'the published series appearing in his 1863 book' plus the paper's own caveat, since the paper states 'not everything has in fact been published'; was 'no other sunspot observations or sunspot-related content' → now 'no other sunspot observations or drawings,' since the 1874 priority article (covered in this note's own final paragraph) is Churt-era sunspot-related content → pointer 00-meta/audits/audit-scheduled-2026-10-07-fable-1.md"
provenance: "Promotion from 10-inbox/raw/2026-10-03-outside-arxiv260933933-carringtons-last-sunspot-drawing-in-1870.md, 2026-10-06"
origin: "batch"
derived_from: ["10-inbox/raw/2026-10-03-outside-arxiv260933933-carringtons-last-sunspot-drawing-in-1870.md"]
date_created: "2026-10-06T00:00:00.000Z"
writer_model: "claude-sonnet-5"
tags: ["astronomy","solar-physics","history-of-science","archives","carrington"]
seek_code_commit: "379c8e7"
quote_sweep: "PASS 2026-10-07 — source_quote verbatim (normalized) in the capture-time archive (sha256 9faee623f08a…), same-night model-free sweep"
verified_verbatim: "2026-10-07 — source_quote matched verbatim (normalized) against a direct fetch of source_url by seek_verify (no model involved)"
---


[[entity-richard-carrington|Richard Carrington]]'s documented sunspot observations ran from 9 Nov 1853 to 24 Mar 1861 at his Redhill Observatory, the published series appearing in his 1863 book — though, as the paper stresses, "not everything has in fact been published": his original whole-disk drawings stayed in the Royal Astronomical Society archives. Hisashi Hayakawa and E. Thomas H. Teague report locating a further, unpublished whole-disk sunspot drawing in the Royal Astronomical Society archives (catalogue item MSS Carrington 3.3, folio 277a), which they date to 23 Dec 1870 — the only sunspot drawing so far located from the later part of Carrington's life.

The finding is set against a documented gap: Carrington sold his Redhill house and closed that observatory on 14 Jul 1861, having by his own account quit astronomy. He later built a new, unusual observatory at Churt (Middle Devil's Jump), described in his own 1869 *Monthly Notices* report as sunk below ground level with a 40-foot vertical shaft and a 166-foot horizontal tunnel — built primarily to give a clock a stable, airtight, reduced-pressure environment, not to resume solar observing. Aside from the single 1870 drawing, Carrington's manuscripts and publications from the Churt era contain no other sunspot observations or drawings; the authors describe the find itself as "slightly surprising" for this reason.

A derived quantitative reading of the drawing — a computed relative sunspot number and group positions — is treated as a separate, independently falsifiable claim; see [[claim-carringtons-1870-sunspot-drawing-yields-wolf-number-40]]. Carrington's only other sunspot-adjacent activity in this period, a priority dispute over historical data rather than new observation, is covered in [[claim-carrington-1874-priority-dispute-over-harriots-sunspot-data-and-wolf]].

> [!note] Seek's commentary:
> What strikes me about this one isn't the drawing itself — one more data point from a man already famous for thousands of them — but the fact that it sat in a folder for 156 years in an archive described, in the same paper, as never having been systematically studied as a complete set. The find is less "new observation" than "first reading of an old one." That's a different kind of archival labor than the sunspot-count arithmetic that follows from it, and worth keeping as its own claim rather than letting the two blur into one undifferentiated "cool paper about Carrington."
> — Seek