Pith Number

pith:W3SIFJ2S

pith:2026:W3SIFJ2SI73HAMLKECN73W7SGS

not attested not anchored not stored refs pending

Hot blue progenitors of stellar-mass black holes

Anna O'Grady, Avishai Gilkis, Charles Kilpatrick, Christopher Tout, Eva Laplace, Maria Drout

Black hole progenitors are predominantly hot and blue at the pre-collapse stage, with many Wolf-Rayet stars that are luminous in the ultraviolet while only a minority are red supergiants.

arxiv:2604.12868 v2 · 2026-04-14 · astro-ph.SR · astro-ph.GA · astro-ph.HE

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{W3SIFJ2SI73HAMLKECN73W7SGS}

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.

Claims

C1strongest claim

We find that black hole progenitors are predominantly hot and blue at the pre-collapse stage, with many in Wolf-Rayet phases and luminous in the ultraviolet, while only a minority are red supergiants.

C2weakest assumption

The physically motivated prescriptions linking pre-collapse core structure to explosion or direct collapse outcome.

C3one line summary

Black hole progenitors are predominantly hot and blue at pre-collapse, often Wolf-Rayet stars luminous in ultraviolet, with only a minority as red supergiants, and a direct-collapse rate of about 0.4 per century for a galaxy with 1 solar mass per year star formation.

Receipt and verification

First computed	2026-05-20T00:04:31.548890Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

b6e482a75247f670316a209bfddbf23481a23924cfa37a0e3262f8a3b20a8d57

Aliases

arxiv: 2604.12868 · arxiv_version: 2604.12868v2 · doi: 10.48550/arxiv.2604.12868 · pith_short_12: W3SIFJ2SI73H · pith_short_16: W3SIFJ2SI73HAMLK · pith_short_8: W3SIFJ2S

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/W3SIFJ2SI73HAMLKECN73W7SGS \
  | 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: b6e482a75247f670316a209bfddbf23481a23924cfa37a0e3262f8a3b20a8d57

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "2b133c1fae60ff6655d7ce409e29398a2d85b34233489ca728faf53981d09b3c",
    "cross_cats_sorted": [
      "astro-ph.GA",
      "astro-ph.HE"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "astro-ph.SR",
    "submitted_at": "2026-04-14T15:18:12Z",
    "title_canon_sha256": "56d704f214747fdec936ac47b61e7bad3ff005ca66d024edfb1aefbd237cb2fd"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.12868",
    "kind": "arxiv",
    "version": 2
  }
}