The View from Sol

THE VIEW FROM THE PLEIADES

A planetarium with time as its main axis: 30,000+ real stars, each moving on its own computed orbit through the Galaxy. Scrub the epoch up to ±50 million years and watch the constellations shear apart.

HOW IT WORKS

Each star is reduced to six numbers — the coefficients of the closed-form epicyclic solution for motion in the linearized local galactic potential (Oort constants A = 15.3, B = −11.9 km/s/kpc). Moving the time slider evaluates those closed forms directly; nothing is integrated at runtime. The 29 bound Pleiades members additionally orbit within a tide-modified 800 M☉ cluster potential. Star colors are real: each star’s measured B–V color index is rendered as its surface temperature — hot stars burn blue-white, cool stars glow orange-red. Trustworthy within a few hundred parsecs of home and ±50 Myr; decorative beyond.

THREE VANTAGE POINTS

SOL — home. ALCYONE — the brightest Pleiad, itself a bound cluster member. HIP 17317 — an old field G-dwarf coincidentally passing through the young cluster: from there you watch the Pleiades sweep by.

WHERE THE DATA CAME FROM

Stars: the HYG v4.1 catalog (Astronexus HYG database — Hipparcos, Yale, Gliese) — every star brighter than magnitude 7.5 as seen from Sol or from Alcyone, plus 13 precomputed close encounters. Constellation figures: Stellarium’s modern (IAU) sky culture. The Milky Way band is procedural art placed in correct galactic coordinates.

HONEST LIMITS

Radial velocity is known for 14,000+ of the stars — the rest move only in the sky plane. Noise-dominated Pleiades member velocities are regularized to the cluster mean (declared in the readout). No stellar evolution — Betelgeuse at +50 Myr is a lie. Distances are Hipparcos-era (about 10% low for the cluster). The system foreground is schematic, not to scale; the space view is to scale.

One of the creations at josephsorensen.com/creations. · BUILD