Pith Number

pith:O27Q46R7

pith:2009:O27Q46R7CRA22Z7LZALTY3Q6QJ

not attested not anchored not stored refs pending

Structural Invariance of Sunspot Umbrae Over the Solar Cycle: 1993-2004

M.J. Penn, T.A. Schad

arxiv:0912.2370 v2 · 2009-12-11 · astro-ph.SR

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{O27Q46R7CRA22Z7LZALTY3Q6QJ}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Receipt and verification

First computed	2026-05-18T04:24:54.821439Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

76bf0e7a3f1441ad67ebc8173c6e1e82588fffb8679f64c76316397c800a002a

Aliases

arxiv: 0912.2370 · arxiv_version: 0912.2370v2 · doi: 10.48550/arxiv.0912.2370 · pith_short_12: O27Q46R7CRA2 · pith_short_16: O27Q46R7CRA22Z7L · pith_short_8: O27Q46R7

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/O27Q46R7CRA22Z7LZALTY3Q6QJ \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 76bf0e7a3f1441ad67ebc8173c6e1e82588fffb8679f64c76316397c800a002a

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "9ed366967dae09b0f8d269faba6c61201c23c8766c7367247635bf9c9e3e3831",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.SR",
    "submitted_at": "2009-12-11T22:15:38Z",
    "title_canon_sha256": "a4c85f4e84a96c3197f0f60d366e70b803eb952bf1e3ed3330ff8da2c9a95b36"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0912.2370",
    "kind": "arxiv",
    "version": 2
  }
}