Hubble captures two eerie shadows moving counterclockwise across planet-forming disk

In 2017, the Hubble Space Telescope captured a shadow sweeping across the face of a vast gas-and-dust disk surrounding a nearby, young star TW Hydrae. The interpretation was a twisted, misaligned inner disk was blocking light from the star and casting a shadow onto the disk's outer region.

Astronomers have now discovered a second shadow around the disk, which could be from yet another disk nestled inside the system. It was found in observations obtained on June 6, 2021, as part of a multi-year program aimed at tracking the shadows in circumstellar disks.

The two disks are thought to be evidence of two planets in the process of formation. The researchers believe that there are two misaligned disks in the system. The two disks were so close to each other in the earlier observation that they were missed. However, over time, they have separated and split into two shadows.

Cosmic construction zone 🚧Misaligned gas-and-dust disks around the young star TW Hydrae are likely caused by the gravitational pull of two developing planets in slightly different orbital planes.Hubble observed shadows cast on the disks as a result: https://t.co/QOIqVUh4rR pic.twitter.com/Rzdl8mUXV1

— Hubble (@NASAHubble) May 4, 2023

TW Hydrae is a red dwarf star that lies 192 light-years away in the constellation Hydra, also known as the Female Water Snake, and is about 8 million years old.

The suspected planets are located at a distance from the star roughly equivalent to the distance between Jupiter and the Sun in our solar system. The shadows complete one rotation around the star approximately every 15 years, which is the expected orbital period for objects located at that distance from the star.

The inclination of the inner disks is also noteworthy - they are inclined about five to seven degrees relative to the plane of the outer disk. This is comparable to the range of orbital inclinations within our own solar system, according to the researchers.

The James Webb Space Telescope (JWST) is expected to provide even more detailed observations of the shadows cast by the disks.