By Ashley Strickland, CNN

(CNN) In 2016, astronomers found a potentially habitable planet called Proxima b around the star Proxima Centauri, which is only 4.2 light-years from Earth. Now, researchers have traced a second signal they believe belongs to a super-Earth orbiting the same star, increasing the intrigue of this neighboring planetary system and its potential.

Proxima Centauri is the closest star to our sun. It co-exists with a binary star in Alpha Centauri. Proxima Centauri is a low-mass red dwarf star known as an M-class dwarf, and it happens to be close to the bright binary star Alpha Centauri AB (which outshines its cool step-brother, so to speak).

All of these stars are within the faint Centaurus constellation, which can’t be seen with the unaided eye.

After the discovery of the first planet around Proxima Centauri, researchers speculated about the existence of another planet in the system. Astronomers used the Atacama Large Millimeter/submillimeter Array of telescopes in Chile to trace light signals that appeared to be coming from that direction.

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