A set of five newly identified exoplanets rotating close to the stars has been detailed in a new study.
The important part of the discovery is two potentially habitable super-Earth planets that are ideal nominees to analyze further as scientists are looking for life outside our Solar System, as per the research team.
Two planets dubbed GJ 180 d and GJ 229A c, weighting 7.5 and 7.9 times the size of Earth, respectively, are located at respective distances of 40 light-years and 19 light-years from our planet.
They both rotate around red dwarf stars, which, overall, is believed not to be a good sign for probable life. That is due to the fact that these kinds of stars use to be rather rough, scourge their vicinity with flare activity and radiation. However, this is not a definite downer, but it depends on the star because some are not so violent.
Is It Actually a Potentially Habitable Place?
A second big issue here is that red dwarfs are rather cooler than the majority of main-sequence stars. Therefore, their Goldilocks zone, where temperatures are useful to liquid water on the surface of a planet, is placed rather close to the star.
This, then, means that planets in that area are more susceptible to tidal locking, where one part of the object is always facing the star, and the other is not. This makes one part of the planet incredibly hot and stellar radiated in a continual manner, while the other side is held in cool darkness.
GJ 180 d has a rotating timeline of 106 days, and the team of researchers theorizes that this particular planet is sufficiently far from its star, Gliese 180, so it would not be tidally locked.
“GJ 180 d is the nearest temperate super-Earth to us that is not tidally locked to its star, which probably boosts its likelihood of being able to host and sustain life,” said astronomer Fabo Feng of the Carnegie Institution for Science.
In the meantime, GJ 229A c has a rotating period of 122 days, but its star, Gliese 229A, is bigger than Gliese 180, so this planet might be tidally locked.
The Black Sheep of the Universe
There is something else that’s pretty amazing about the star; more precisely, Gliese 229A is in a binary system with a brown dwarf star, Gliese 229B. These cosmic bodies are, at times, called ‘failed stars,’ which means they are too massive to be a planet but too small to merge hydrogen in their nucleus.
They take shape in an identical way the stars do, from the gravitational crash of a clump of gas, contrary to the slow accretion process that gives life to planets. However, it is not clear if they can host planets.
The planets were identified using an indirect method, known as radial velocity. Even though it may not seem so, planets rotating a star have a gravitational impact on that star, making it ‘wobble’ a bit as the planet pulls it.
Due to the fact that these particular systems are in close proximity, the scientists suggest that the next generation of advanced telescopes could ultimately provide them with direct images of these objects; therefore, helping them better understand whether the planet has an atmosphere or even water, and so on.
“Our discovery adds to the list of planets that can potentially be directly imaged by the next generation of telescopes,” Feng said. “Ultimately, we are working toward the goal of being able to determine if planets orbiting nearby stars host life.”
The paper has been published in The Astrophysical Journal Supplement Series.