The making of a shadow in TW Hydrae's disc (illustration)

This illustration reveals the proposed structure of the gas and dust disc surrounding the nearby, young star TW Hydrae. It shows an inner disc that is tilted due to the gravitational influence of an unseen companion, which is orbiting just outside the disc.

The tilted inner disc is the best explanation for a shadow covering part of the disc's outer region. The warped disc is blocking light from the star and casting the shadow across the disc. The nature of the darkening was first revealed in Hubble Space Telescope archival observations, which showed that the feature moved around the star at a much faster rate than any phenomenon that would be physically linked to the slowly rotating disc.

TW Hydrae is about 8 million years old and resides about 190 light-years from Earth.

Links:

• NASA Press release
• Shadow on TW Hydrae’s disc