Pith Number

pith:BMSAYX7W

pith:1997:BMSAYX7WZC7KT65SGFAJAFHFRG

not attested not anchored not stored refs pending

The Double Quasar Q2138-431: Lensing by a Dark Galaxy?

A.F. Heavens, D. Clements, Edinburgh), E.M. Minty, J.W. Fried, M.R.S. Hawkins (Royal Observatory, P. van der Werf, P. V\'eron

arxiv:astro-ph/9709049 v1 · 1997-09-05 · astro-ph

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{BMSAYX7WZC7KT65SGFAJAFHFRG}

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	2026-05-18T01:09:21.472388Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

0b240c5ff6c8bea9fbb231409014e589a090b648fdc5e1df710312121d66ecf4

Aliases

arxiv: astro-ph/9709049 · arxiv_version: astro-ph/9709049v1 · doi: 10.48550/arxiv.astro-ph/9709049 · pith_short_12: BMSAYX7WZC7K · pith_short_16: BMSAYX7WZC7KT65S · pith_short_8: BMSAYX7W

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/BMSAYX7WZC7KT65SGFAJAFHFRG \
  | 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: 0b240c5ff6c8bea9fbb231409014e589a090b648fdc5e1df710312121d66ecf4

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "da210dd4a3bfb5aa86a4fc5f2d8d8f4716233d6761ca122c9f6a4e33b79021d8",
    "cross_cats_sorted": [],
    "license": "",
    "primary_cat": "astro-ph",
    "submitted_at": "1997-09-05T11:39:06Z",
    "title_canon_sha256": "acd342819123fc1f2759c8ab69a1964018e364afdd93d6698754ee6ea1588d22"
  },
  "schema_version": "1.0",
  "source": {
    "id": "astro-ph/9709049",
    "kind": "arxiv",
    "version": 1
  }
}