Astrometric exoplanet discovery relies on detection of stellar motion caused by planetary companions. Systems with orbital period close to one year may escape detection if orbital motion of ...

This article originally published at Earth just got a new companion in space. It's sticking around for 60 years.. A one-way ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

Astronomers had long suspected that certain quasars—those brilliant, otherworldly light sources fueled by supermassive black ...

Astronomers observe for the first time the actual motion of spirals in a protoplanetary disk, revealing gravitational ...

The apparent brightness of celestial objects, rather than their proximity, is the primary factor determining observability. Andromeda Galaxy, despite its vast distance, appears significantly brighter ...