How Gravitational Waves Can Reveal Unknown Alien Planets in Distant Galaxies

Changing the way we hunt for alien planets.

If we are to find whether or not we are alone in the universe, we need to ramp up our game in search of distant alien worlds.

And exploring the universe in search for exoplanets may just get a lot easier.

According to reports, the future LISA gravitational wave observatory will be able to detect exoplanets that orbit binaries of white dwarfs in the Milky Way and in the nearby Magellanic Clouds.

This new way of hunting alien planets was revealed by researchers from the Max Planck Institute for Gravitational Physics (AEI) and the French Commission for Alternative Energies and Atomic Energy (CEA), using a new method described in Nature Astronomy.

This new method will overcome certain limitations of current electromagnetic detection techniques and could allow LISA to detect planets of up to 50 times the mass of Earth.

In the last two decades, knowledge of exoplanets has grown exponentially, and more than 4,000 planets have been discovered orbiting a wide variety of stars.

Until now, the techniques used to find and characterize these exoplanets and their home systems were based on electromagnetic radiation and are limited to the solar neighborhood and some parts of the galaxy.

But this could soon change.

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Artist's impression of the exoplanet Proxima Centauri b shown as of a arid (but not completely water-free) rocky Super-Earth. This appearance is one of several possible outcomes of current theories regarding the development of this exoplanet, while the actual look and structure of the planet is known in no ways at this time. Proxima Centauri b is the closest exoplanet to the Sun and also the closest potentially habitable exoplanet as well. Image Credit: Wikimedia Commons.
Artist’s impression of the exoplanet Proxima Centauri b shown as of an arid (but not completely water-free) rocky Super-Earth. Image Credit: Wikimedia Commons.

Scientists have proposed a new method that makes use of gravitational waves in order to find exoplanets that orbit binary white dwarfs.

white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to that of the Sun, while its volume is comparable to that of Earth.

“LISA will measure the gravitational waves of thousands of white dwarf binaries. When a planet is in orbit around a pair of white dwarfs, the observed pattern of gravitational waves will look different compared to that of a binary without a planet, and therefore gravitational waves will allow us to discover exoplanets,” the scientists revealed in a new study.

The advantage of gravitational waves is that they are not affected by stellar activity, which can impede electromagnetic discoveries.

In their study’s paper, Tamanini and his colleague Camilla Danielski show that the next LISA mission of the ESA (Laser Interferometer for Space Antennas), scheduled for launch in 2034, can detect Jupiter mass exoplanets around white dwarf binaries throughout the galaxy, overcoming the limitations in the distance of electromagnetic telescopes.

In addition, they point out that LISA will have the potential to detect these exoplanets also in nearby galaxies, revealing the first extragalactic exoplanet.

“LISA is going to target an exoplanet population yet completely unprobed,” explains Tamanini. “From a theoretical perspective, nothing prevents the presence of exoplanets around compact binary white dwarfs.”

“If these systems exist and are found by LISA, scientists will obtain new data to further develop planetary evolution theory. They will better understand the conditions under which a planet can survive the stellar red-giant phase(s) and will also test the existence of a second generation of planets, i.e., planets that form after the red-giant phase. On the other hand, if LISA does not detect exoplanets orbiting white dwarf binaries, the scientists will be able to set constraints on the final stage of planetary evolution in the Milky Way,” reports Phys.org.

Via
Phys.org