Pith Number

pith:E56WULSX

pith:2026:E56WULSXGOIE5AR3S2J6FQEMJ7

not attested not anchored not stored refs resolved

Fundamental properties of two rapidly rotating stars: Rasalhague and Alkaid

Alain Hui-Bon-Hoa, Axel Lazzarotto, Matthew Gent, Michel Rieutord, Torsten Boehm

A method using infrared temperatures, projected velocities, and luminosities with grids of two-dimensional stellar models determines masses, rotation rates, ages, and spin-axis inclinations for fast-rotating stars.

arxiv:2604.11189 v1 · 2026-04-13 · astro-ph.SR

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\usepackage{pith}
\pithnumber{E56WULSXGOIE5AR3S2J6FQEMJ7}

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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

Using the temperature derived by the infrared flux method, the Vsini and the apparent luminosity, along with a grid of 2D steady state models, we select models that are compatible with all observational constraints, and derive the most probable mass, rotation rate, core hydrogen mass fraction relative to that of the envelope, and inclination of the rotation axis on the line of sight of the targeted star.

C2weakest assumption

The assumption that the steady 2D models accurately capture the internal structure and surface properties of the real stars without missing time-dependent or magnetic effects, and that the five observables are sufficient to break degeneracies among mass, rotation rate, age, and inclination.

C3one line summary

A grid of 2D steady-state models combined with temperature, luminosity, and Vsini data yields mass 5.071 M⊙, 14.6-hour rotation period, and 42° inclination for Alkaid plus refined parameters and 69° inclination for Rasalhague.

References

2 extracted · 2 resolved · 0 Pith anchors

[1] Abe, S., Abhir, J., Acciari, V . A., et al. 2024, MNRAS, 529, 4387 Abt, H. A. & Morrell, N. I. 1995, ApJ Supp. Ser., 99, 135 Asplund, M., Grevesse, N., Sauval, A. J., & Scott, P. 2009, Ann. Rev. Astro 2024

[2] Cambridge, 13 Lazzarotto, A., Hui-Bon-Hoa, A., & Rieutord, M. 2023, A&A, 676, A50 Manchon, L., Deal, M., Marques, J. P. C., & Lebreton, Y . 2025, A&A, 704, A79 Mombarg, J. S. G., Dotter, A., Rieutord, 2023

Receipt and verification

First computed	2026-05-27T14:06:43.532692Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

277d6a2e5733904e823b9693e2c08c4ff6051e741083b2a5f446230989cd1c57

Aliases

arxiv: 2604.11189 · arxiv_version: 2604.11189v1 · doi: 10.48550/arxiv.2604.11189 · pith_short_12: E56WULSXGOIE · pith_short_16: E56WULSXGOIE5AR3 · pith_short_8: E56WULSX

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/E56WULSXGOIE5AR3S2J6FQEMJ7 \
  | 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: 277d6a2e5733904e823b9693e2c08c4ff6051e741083b2a5f446230989cd1c57

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "b8e94e59aed7474d42181de169904a4268f81d7ea2625131ab9f11064af59886",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.SR",
    "submitted_at": "2026-04-13T08:48:27Z",
    "title_canon_sha256": "1951427149878feb13a97caf20a46dfeaad9919753622def4c503989600ce11a"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.11189",
    "kind": "arxiv",
    "version": 1
  }
}