'Closest Multi-Planetary System To Us' – Light Signals Observed From Potential Super-Earth Just 4 Light-Years Away
A new signal emanating from space has been traced to what astronomers believe is a new super-Earth orbiting our second-closest star, after the Sun: CNN reports that astronomers picked up faint light signals that appeared to be coming from what they believe may be a second potentially habitable planet orbiting the nearby star Proxima Centauri.
Proxima Centauri is a red dwarf star that is part of the Alpha Centauri star system. From Earth, these three stars appear as the third brightest star in our sky. Of these three, Proxima Centauri is the closest to Earth – just over four light-years away. This new planet – simply named Proxima c – is believed to be a super-Earth somewhere between the size of Earth but no bigger than Neptune and orbits Proxima Centauri approximately every five Earth years.
Astronomers picked up faint light signals that appeared to be coming from what they suspect is the planet using a fleet of telescopes in the Chilean desert called the Atacama Large Millimeter Array. Then, they compared these signals to radial velocity measurements taken over 17 years.
The radial velocity method is, according to the Planetary Society, a method of detecting planets we can't yet see orbiting a star by examining how the planet's gravity affects the star's motion. We do this by observing the frequencies of light that are emitted: If the star is moving towards us, the light it gives off moves toward the blue end of the spectrum. If the star is moving away, the color warms up as it shifts back towards the red end of the spectrum. If a star keeps shifting between the two consistently, that is almost certain evidence of a planet present that is acting on the star.
Fabio Del Sordo, the author of this study that was just published in the journal Science Advances and is a postdoctoral physics researcher at the University of Crete told CNN in an email:
"Proxima Centauri is the nearest star to the sun, and this detection would make it the closest multiplanetary system to us."
Cover Image: ESO/M. Kornmesser CC BY 4.0