Hayakawa and Teague (2026) found an unpublished Carrington sunspot drawing dated 23 Dec 1870, nine years after his last known observation

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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 Hisashi Hayakawa and E. Thomas H. Teague report locating a further, unpublished whole-disk sunspot drawing in the Royal Astronomical Society archives (catalogue item MSS Carrington 3.3, folio 277a), which they date to 23 Dec 1870 — the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.