Albert Einstein Institute, Potsdam | Max Planck Institute for Gravitational Physics | 2019 Jul 08
Researchers propose a method by which the LISA space observatory could one day work
In a recent paper in Nature Astronomy, researchers from the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) in Potsdam and from the French Alternative Energies and Atomic Energy Commission (CEA) in Saclay, Paris suggest how the planned space-based gravitational-wave observatory LISA can detect exoplanets orbiting white dwarf binaries everywhere in our Milky Way and in the nearby Magellanic Clouds. This new method will overcome certain limitations of current electromagnetic detection techniques and might allow LISA to detect planets down to 50 Earth masses.Artistic representation of gravitational waves produced by a compact
binary white dwarf system with a jovian mass planetary companion.
© Artwork by Simonluca Definis
In the past two decades, our knowledge of exoplanets has grown significantly, and more than 4000 planets orbiting a large variety of stars have been discovered. Up to now, the techniques used to find and characterize these systems are based on electromagnetic radiation and are limited to the solar neighborhood and some parts of our Galaxy. ...
The new method exploits the Doppler shift modulation of the gravitational-wave signal caused by the gravitational attraction of the planet on the white dwarf binary. This technique is the gravitational-wave analogue of the radial velocity method, a well-known technique used to find exoplanets with standard electromagnetic telescopes. The advantage, however, of gravitational waves is that they are not affected by stellar activity, which can hamper electromagnetic discoveries.
In their paper, Tamanini and Danielski show that the upcoming ESA mission LISA (Laser Interferometer Space Antenna), scheduled for launch in 2034, can detect Jupiter-mass exoplanets around white dwarf binaries everywhere in our Galaxy, overcoming the limitations in distance of electromagnetic telescopes. Furthermore, they point out that LISA will have the potential to detect those exoplanets also in nearby galaxies, possibly leading to the discovery of the first extragalactic bound exoplanet. ...
The Gravitational-Wave Detection of Exoplanets Orbiting White Dwarf Binaries Using LISA ~ Nicola Tamanini, Camilla Danielski
- Nature Astronomy (online 08 Jul 2019) DOI: 10.1038/s41550-019-0807-y
- arXiv.org > astro-ph > arXiv:1812.04330 > 11 Dec 2018 (v1), 12 Dec 2018 (v2)