Search the Stars.

Astroneo is an astronomy reference built around two things: a catalogue of 8,898 celestial objects with their measured properties, and a set of written guides that explain what those measurements mean.

The catalogue draws on the HYG database — a compilation of the Hipparcos, Yale Bright Star and Gliese catalogues — so coordinates, magnitudes, distances and spectral classes are the same values professional astronomers work with. You can filter the catalogue by constellation or spectral class, and every object has an interactive 3D model and a visibility checker that uses your location to tell you whether it is above the horizon right now.

Alongside that, a few dozen objects have full written articles — how Betelgeuse dimmed in 2019 and why, why Vega is egg-shaped, what the first photograph of a black hole actually shows. The articles cover stellar physics, cosmology and practical observing, including honest advice on buying a first telescope and what you will realistically see through it.

Every article lists the sources it draws on. Where something is genuinely unsettled — Deneb’s distance, how supermassive black holes grew so fast, whether dark energy is constant — it says so rather than picking an answer. The remaining catalogue entries are reference pages showing measured data, and they are labelled as such.

Everything is free, and there is no account required to read any of it.