New York: Astronomers have detected a repeating radio signal from an exoplanet and the star that it orbits, both located 12 light-years away from Earth. The signal suggests that the Earth-size planet may have a magnetic field and perhaps even an atmosphere.
Earth’s magnetic field protects the planet’s atmosphere, which life needs to survive, by deflecting energetic particles and plasma that stream out from the sun. Finding atmospheres around planets located outside of our solar system could point to other worlds that potentially have the ability to support life.
Scientists noticed strong radio waves coming from the star YZ Ceti and the rocky exoplanet that orbits it, called YZ Ceti b, during observations using the Karl G. Jansky Very Large Array of telescopes in New Mexico. The researchers believe the radio signal was created by interactions between the planet’s magnetic field and the star.
“We saw the initial burst and it looked beautiful,” said lead study author Sebastian Pineda, a research astrophysicist at the University of Colorado Boulder, in a statement. “When we saw it again, it was very indicative that, OK, maybe we really have something here.”
Magnetic fields can prevent a planet’s atmosphere from being diminished and essentially eroded away over time as particles release from the star and bombard it, Pineda said.
Their findings are published in the journal Nature Astronomy.
“Whether a planet survives with an atmosphere or not can depend on whether the planet has a strong magnetic field or not,” explained Pineda.
Villadsen first isolated the radio signal while pouring over data at her home on a weekend.
As plasma from YZ Ceti careens off the planet’s magnetic “plow,” it then interacts with the magnetic field of the star itself, which generates radio waves strong enough to be observed on Earth.
The strength of the planet’s magnetic field can then be measured by measuring that of the radio waves thus emitted.
“The search for potentially habitable or life-bearing worlds in other solar systems depends in part on being able to determine if rocky, Earth-like exoplanets actually have magnetic fields,” says National Science Foundation’s (NSF’s) Joe Pesce, program director for the National Radio Astronomy Observatory.
“This research shows not only that this particular rocky exoplanet likely has a magnetic field but provides a promising method to find more.”