Tilted binary stars test theories of planet formation

Cockeyed planet nurseries may shape orbits of future solar systems

HK Tauri

SIDE VIEW  A disk of dust blocks light from one star (bottom) in HK Tauri, a binary system about 525 light-years away, in this image from the Hubble Space Telescope. New data reveal a disk, not visible in this picture, around the companion star (top).

Karl Stapelfeldt/JPL/NASA

Exoplanet orbits come in all shapes and sizes, and a pair of nearby stars is helping astronomers figure out why.