The inner planet of the system, named LP890-9b, is about 30 percent larger than Earth and orbits the star in just 2.7 days. This first planet was initially identified as a possible planet candidate by NASA's TESS exoplanet-hunting telescope.
"It is important to detect as many temperate terrestrial worlds as possible to study the diversity of exoplanet climates, and eventually to be in a position to measure how frequently biology has emerged in the cosmos," Amaury Triaud, a professor of exoplanetology at the University of Birmingham, said in a statement.
The observations of LP 890-9b made by SPECULOOS proved fruitful, as they not only confirmed the presence of the first planet, but also played a crucial role in the discovery of the second, previously unknown planet.
This second planet, LP 890-9c, is similar in size to the first (about 40 percent larger than Earth), but has a longer orbital period - about 8.5 days. At its orbital position, the exoplanet sits within its star's conservative habitable zone, receiving stellar radiation levels similar to Earth.
The telescopes of the SPECULOOS project installed at the Paranal Observatory of the European Southern Observatory in the Atacama Desert in Chile, and on the island of Tenerife, are optimized for high-precision observation of these types of stars thanks to cameras that are very sensitive in the near infrared range.
Earlier, NASA reported that a space telescope named after James Webb photographed its first exoplanet. According to scientists, this achievement was "a historic moment for astronomy".