Article by: Andacs Robert Eugen, on 09 September 2022, at 09:01 am Los Angeles time

The two planets discovered by astronomers orbit a small, cold star called LP 890-9. This is the second coolest planet-hosting star, after TRAPPIST-1, an equally interesting star. 

One of the planets in the system is known as LP 890-9b and is only 30% larger than Earth. It is so close to this cold star that a year lasts only 2.7 days. 

The system also contains another, completely unknown planet, which has been named LP 890-9c. It is similar in size to the first - it is 40% larger than Earth - but a year longer, taking 8.5 days to orbit its star.

The new research was carried out with the help of ground-based telescopes called Speculoos - Search for habitable Planets EClipsing ULtra-cOOl Stars. Very cool stars like LP 890-9b require these kinds of follow-up observations because space telescopes can have a hard time detecting them. 

Scientists had begun this research in hopes of confirming the existence of the first planet, which was first detected as a potential world by Nasa's Transiting Exoplanet Survey Satellite, which searches for planets outside our solar system. 

But the observations also discovered the second planet. This planet is in the star's "habitable zone," meaning it is neither too hot nor too cold to host alien life. 

"The habitable zone is the concept that a planet with similar geological and atmospheric conditions to Earth would have a surface temperature that would allow water to remain liquid for billions of years," said Amaury Triaud, a professor at the University of Birmingham and leader of the working group that made the observations that led to the discovery of the second planet. 

"This gives us the opportunity to observe more and find out if the planet has an atmosphere, and if so, to study its contents and assess its habitability."