This tool maps the AAVSO Variable Star Index (VSX) cross-matched with Gaia DR3 — over 10 million variable stars. Each View projects that population into a different scientific plane. Colour shows the density of stars per pixel (log scale) unless you pick a categorical scheme. Everything runs in your browser on a representative rasterisation of the full catalog.
An all-sky density map (Mollweide equal-area). The bright band across the middle is the Milky Way's disk, where both stars and the surveys that find them concentrate; the two blobs at lower right are the Magellanic Clouds, and the sweeping arcs are the footprints of surveys like Gaia. It answers: where on the sky do variable stars live, and how have we looked?
Pulsation or orbital period (log) against brightness amplitude (log). Classes cluster in distinct regions: short-period low-amplitude pulsators (δ Sct) at lower left, the RR Lyrae strip near half a day, contact binaries against their ~0.22-day period floor, and the long-period, large-amplitude Miras at upper right. A quick "what kind of variable is this?" diagnostic.
Period against absolute magnitude MG (brighter upward). This is the plane of the Leavitt Law: for pulsators such as Cepheids and RR Lyrae, period and luminosity are tightly linked — the relation that anchors the cosmic distance ladder. Absolute magnitude requires the Gaia distance, so this view covers the Gaia-matched subset.
Period against Gaia colour (BP−RP). Pulsation period correlates with temperature along the instability strip, so pulsator families trace characteristic period–colour sequences. The coolest, reddest, longest-period objects at upper right are the Mira/long-period giants.
The Hertzsprung–Russell diagram: Gaia colour BP−RP (hot blue at left → cool red at right) against absolute magnitude MG (brighter up). Stars fall on the main sequence (the diagonal), the red-giant branch (upper right), and the faint white-dwarf sequence (lower left). The strip along the top maps colour to spectral type (O–M) and approximate temperature. Colour it by category to see how variability tracks evolutionary state.
A distance-free stand-in for the HR diagram. Reduced proper motion HG = G + 5·log₁₀μ + 5 substitutes a star's proper motion μ (its yearly drift across the sky) for a measured distance: nearby dwarfs move fast, distant giants slowly, so HG separates luminosity classes on its own. Because it needs no parallax, it covers far more stars than the HR or period–luminosity views.
Values are drawn from AAVSO VSX × Gaia DR3 and are not independently validated. Absolute magnitudes use Gaia GSP-phot distances. Source: The Variable Zoo Project (variablezoo.org).
