The Making of a Shadow in TW Hydrae's Disk
This diagram reveals the proposed structure of a gas-and-dust disk surrounding the nearby, young star TW Hydrae.
The illustration shows an inner disk that is tilted due to the gravitational influence of an unseen companion, which is orbiting just outside the disk.
The tilted inner disk is the best explanation for a shadow covering part of the disk's outer region. The warped disk is blocking light from the star and casting the shadow across the disk. 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 disk.
TW Hydrae is about 8 million years old and resides 192 light-years from Earth.