Pith Number

pith:Y6JIJ2VP

pith:2026:Y6JIJ2VP6P6JD3UCKELWQDAOXU

not attested not anchored not stored refs pending

X-Shooting ULLYSES: Massive stars at low metallicity XV. On the metallicity dependence of B-supergiant mass-loss rates

A.A.C. Sander, A. C. Gormaz-Matamala, A. de Koter, C. Hawcroft, C. Van der Sijpt, D. Debnath, D. Pauli, F. Backs, F. Najarro, F. Tramper, H. Sana, H. Todt, J.O. Sundqvist, J.S. Vink, J.Th. van Loon, M. Bernini-Peron, N. Moens, O. Verhamme, P.A. Crowther, P.Schillemans, R.Kuiper, S. A. Brands, S. R. Berlanas, Xshootu collaboration

B-supergiant mass-loss rates exhibit weak metallicity dependence and lack the predicted bi-stability jump, providing new empirical constraints on line-driven wind models.

arxiv:2604.21452 v2 · 2026-04-23 · astro-ph.SR

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\usepackage{pith}
\pithnumber{Y6JIJ2VP6P6JD3UCKELWQDAOXU}

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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

The metallicity trends present in the mass-loss prescriptions (Z^(0.41-1.4)) explored here overestimate the empirical metallicity dependence in the B-star regime, which appears very weak. We do not find an increase in mass-loss rate at approximately spectral type B1.

C2weakest assumption

That simultaneous fitting of UV and optical spectra with fastwind and Kiwi-GA yields unbiased wind parameters, including clumping factors, across the 13-29 kK temperature range without significant systematic errors from model assumptions or data quality.

C3one line summary

B-supergiant mass-loss rates exhibit weak metallicity dependence and lack the predicted bi-stability jump, providing new empirical constraints on line-driven wind models.

Receipt and verification

First computed	2026-06-10T14:10:50.876845Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

c79284eaaff3fc91ee825117680c0ebd3e083c484e3c44312de30073eae7a041

Aliases

arxiv: 2604.21452 · arxiv_version: 2604.21452v2 · doi: 10.48550/arxiv.2604.21452 · pith_short_12: Y6JIJ2VP6P6J · pith_short_16: Y6JIJ2VP6P6JD3UC · pith_short_8: Y6JIJ2VP

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/Y6JIJ2VP6P6JD3UCKELWQDAOXU \
  | 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: c79284eaaff3fc91ee825117680c0ebd3e083c484e3c44312de30073eae7a041

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "116fdef854e963216c2e6a89850b983e0ab14b8273b1dfafc2827a5023db6cbf",
    "cross_cats_sorted": [],
    "license": "http://creativecommons.org/licenses/by-nc-sa/4.0/",
    "primary_cat": "astro-ph.SR",
    "submitted_at": "2026-04-23T09:11:46Z",
    "title_canon_sha256": "70cbec459993332bd1dd945015048eff73cb8086e5c6f2f6bb2cd7e4c2606e67"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.21452",
    "kind": "arxiv",
    "version": 2
  }
}