How a planet’s tug could show up in gravitational waves
Researchers modelled how the future LISA observatory might find planets orbiting two white dwarfs.
A planet can reveal itself by pulling on the objects it orbits. Two studies described by NASA examine whether that pull could be measured in gravitational waves from pairs of white dwarfs, the remnants of stars like the Sun.
A tight pair of white dwarfs produces gravitational waves as the stars circle one another. A sufficiently massive planet orbiting the pair would make the pair move slightly in response. As it moves toward and away from an observer, the frequency of the waves shifts. Researchers modelled whether the future Laser Interferometer Space Antenna, or LISA, could pick up that pattern.
The work describes a detection method for a mission still in development. The European Space Agency leads LISA, with NASA contributing hardware and expertise. A companion study explores whether the James Webb Space Telescope could help confirm some of the closer candidates.