Researchers have found potentially habitable planets in a nearby star system, which is 12 light-years away. However, further research needs to be made in order to call them compatible enough for human survival.
In a paper uploaded to the arXiv preprint server, and soon to be published in Monthly Notices of the Royal Astronomical Society by scientists from European countries and one from Chile, they stated the not only one but three planets are in an ideal setting to host human life.
According to their findings, the three almost Earth-sized planets orbit a star that’s currently called GJ1061. Additionally, it is the 20th nearest known star system from our own.
Data about the star, which were collected using the HARPS instrument on the 3.6-meter telescope from the European Southern Observatory in Chile, showed that the three exoplanets orbiting GJ1061 have a mass of about 1.4 to 1.8 times than that of the Earth.
Astronomers observed the star over 54 nights from July to September in 2018. The star was one target of a larger campaign called the Red Dot project, which since 2017 has surveyed small nearby stars to look for terrestrial planets like Earth.
Furthermore, researchers used a technique called radial velocity where a telescope tries to decipher small movements from a star’s orbit, which indicate planetary gravity pulling on it.
In the past, this method of detecting planets was only used for much bigger ones but recent improvements with technology have allowed it to also find smaller ones, which yielded to the discovery of these three planets.
All three of which orbits in close vicinity of the star, closer than Mercury is to the Sun. Thus, a year on the planets lasts from three to 13 earth days, whereas a year represents the amount of time a planet makes a full revolution on its star.
In contrast, Mercury completes a revolution every 88 Earth-days.
Despite the fast revolution rate of the planets and close proximity to its star, scientists are particularly interested with the one that’s farthest from the three, the one that lasts 13 days, which they are calling “planet d.”
Specifically “planet d” orbits in an area astronomers like to call the “Goldilocks Zone.” Similar to the popular childhood story, the Goldilocks Zone is a specific region in a star system where it’s just right. It’s not too hot nor too cold.
In contrast to planet d where it is in an ideal position that it can be considered habitable because it is in a zone where liquid water could exist on the surface. Most likely, the temperature of the planet keeps the water in liquid form, which is a key element to sustain life.
Meanwhile, the host star GJ1061 is a type of low-mass star called an M dwarf or a Red dwarf, which are the smallest and coolest kind of star to be known. Furthermore, Red dwarfs are the most common type of star in the Milky Way, at least in the neighborhood of the Sun, but because of their low luminosity, individual Red dwarfs cannot be easily observed.
Essentially, GJ1061 is similar to Proxima Centauri, the star closest to Earth—approximately 4.2 light-years away.
In 2016, researchers also discovered that Proxima Centauri is also able to host habitable planets but it also showed to have a consistent stellar activity that could to be dangerous and harmful to humans.
Recognizing the potentially harmful environment that could result from Proxima Centauri, researchers have instead looked at other nearby stars such as GJ1061, who shows to have a less violent stellar activity.
On the other hand, scientists also noted that a planet’s habitability cannot only be measured by present data. Essentially, they will also have to look at the planet’s history.
According to the researchers, it is not impossible that GJ1061 was also as hostile and as violent as Proxima Centauri. In other words, it could have also been once a star that radiated intense stellar activity, which would have exposed planet d to millions of years of solar radiation, rendering the planet uninhabitable as it may no longer be able to retain a life-sustaining atmosphere.
As for now, further research is still needed to determine if planet d is habitable. It may also take some time as scientists are only capable of doing said research from afar.