slow-VGRF

Stars that have almost stopped moving — in the frame of the Galaxy.

The instantaneous Galactic rest-frame speed VGRF = |vgalactocentric| of a typical disc star is a few hundred km s⁻¹. This site is the interactive companion to A Probabilistic Gaia DR3 Catalogue of Stars with Very Low Galactic Rest-Frame Speeds (Humble 2026): a probability-scored sample of stars with P(VGRF< 25 km s⁻¹) — stars caught near an orbital turning point with almost no angular momentum. In any centrally concentrated potential they must fall back toward the inner Galaxy: their orbits are nearly radial plunges. Here you can browse every candidate, follow each step of the math, and integrate the orbits yourself — in the paper's own galactic potential models, live in your browser.

541
Tier A+B stars
P(V_GRF < 25 km/s) > 0.84 — the primary catalogue
1952
Tier A+B+C with orbits
P > 0.50, integrated 4 Gyr in each model
0.964
median eccentricity
point-estimate, adopted static model
116 pc
median pericentre
864 stars reach R < 100 pc (static); 1635 with the bar

3D orbit viewer

Pick any of the 1952Tier A+B+C stars, choose a galactic potential model (static Hunter+2024, McMillan 2017, or the barred models across the paper's Ωp grid) and watch its 4-Gyr orbit integrate live — with the Sun and well-measured context stars for scale, and overlays that show the model itself at work.

Catalogue browser

Filter and search all 20,829 candidate sources by tier, membership probability, quality flags and chemistry; every star has a full detail page with Monte Carlo orbit posteriors and both-model orbit summaries.

The math, step by step

From five Gaia numbers to a catalogue probability: parallax zero-point, Bailer-Jones distance, the exact Galactocentric transform (all four solar-frame variants), VGRF, and the Monte Carlo tiering — with live numbers for real stars.

Ensemble figures

Interactive versions of the paper's key figures: pericentre vs apocentre, E–Lz, the Toomre diagram, the sky map, and the smooth-continuation excess.

Provenance & caveats

Release v1.0.8-review, DOIs, licensing — and the honest fine print: which numbers are model outputs, where actions are unreliable, and how the in-browser engine is validated against the published catalogue.