10 months ago
When scientists first observed the star HL Tauri, there appeared to be a “glowing disk split by crisp bands,” which led to the thought that unseen planets were carving out paths as they orbited. But new simulations suggest a more complex picture, reports Scientific American. The gaps seen may actually be a result of gravitational tugs of planets elsewhere on the disk, or even outside of the disk. Learning more about these patterns could speed up the detection of hard-to-find planets.
Maryam Tabeshian, the developer of the model and researcher at Western University in Ontario, told Scientific American, “We’re going to start seeing more of these coming out very soon, a lot of these beautiful, high signal-to-noise ratio disks that we can see with these structures.”
Tabeshian thinks relying on orbital jostling motions will help the search for unseen planets. The dust-and-gas disks look solid, but they’re not. Instead, they are composed of grains, boulders, and mini-planets all orbiting at different speeds. Each time a planet aligns with a particle, it gives it a “gravitational nudge,” which can push the planet from the disk entirely. When planets are ejected from the disk, they leave holes. Scientists think that they can predict the planet’s mass and orbit using the width, location, and shape of the gap, according to Scientific American.
However, it will be difficult, because the view of these disks from Earth has to be just right, and the patterns sit right on the technical edge of what current tools can resolve. But as the process goes on, techniques will be refined, and direct images will try to find planets closer to their bright host stars.