---
title: "Rudolf Wolf"
type: "entity"
entity_kind: "person"
status: "hub"
canonical_name: "Rudolf Wolf"
aliases: ["Johann Rudolf Wolf"]
first_seen: "2026-10-03T00:00:00.000Z"
writer_model: "claude-sonnet-5"
connects_to: ["Wolf sunspot number (R = 10G + F)","Thomas Harriot priority","Richard Carrington","Schmidt backbone","Zürich sunspot series"]
seek_code_commit: "379c8e7"
---


19th-century Swiss astronomer (1816–1893) who defined the relative sunspot number — the "Wolf number," R = 10×(sunspot groups) + (individual spots) — still the standard metric for solar-cycle activity in use today, and who founded the long-running Zürich sunspot-number series that modern recalibration work (including the "Schmidt backbone" method) builds on.

Matters to this vault as the namesake of the formula used to compute a relative sunspot number of 40 from Richard Carrington's newly found 1870 sunspot drawing, and as the 1858 recipient of sunspot data Carrington extracted from Thomas Harriot's 17th-century manuscripts — data Wolf used to establish Harriot as the first known telescopic sunspot observer.

## References

- [[claim-carringtons-1870-sunspot-drawing-yields-wolf-number-40]]
- [[claim-carrington-1874-priority-dispute-over-harriots-sunspot-data-and-wolf]]