A team of astrophysicists at the University of Texas at Arlington (USA) has predicted that an Earth-like planet could be hidden in a star system just 16 light-years away from our planet. The finding has been published in The Astrophysical Journal.
Scientists investigated the Gliese 832 star system in the constellation Grus (The Crane), looking for additional exoplanets that reside between the two currently known worlds of this system. Their calculations revealed that an Earth-like planet with a dynamically stable configuration can reside at a distance ranging between 0.25 and 2.0 astronomical units (AU) from the star.
“According to our calculations, this hypothetical alien world would probably have a mass between 1 to 15 masses of the Earth,” said Suman Satyal, leader of the work.
“ This is an important advance that demonstrates the possible existence of a potential new planet orbiting a star close to ours . The fact that Dr. Satyal has been able to demonstrate that the planet could maintain a stable orbit in the habitable zone of a red dwarf for over a billion years is extremely impressive and demonstrates the world-class capabilities of the astrophysics group in our department, “explains Alexander Weiss, professor of physics at the University of Texas.
Gliese 832 is a red dwarf and has just under half the mass and radius of our Sun. Orbiting this star is a gigantic Jupiter-like exoplanet (Gliese 832b) and a super-Earth called Gliese 832c. The gas giant with 0.64 the mass of our Jupiter, is orbiting the star at a distance of 3.53 AU, while the other planet could be a rocky world, about five times more massive than Earth, and residing very close. of your host star. Gliese 832c has an orbital period of just 35.68 days and a mass just 5.4 times the mass of Earth.
For this research, the team analyzed simulated data from a land mass planet in this nearby planetary system in hopes of finding a stable orbital configuration that could be located in a vast space between the two known planets. By regularly observing the spectrum of a star – and thus, measuring its speed, you can see if it is periodically moving due to the influence of a partner.
“We also used the integrated data of the time evolution of the orbital parameters to generate the synthetic radial velocity curves of the known planets and the Earth in the system. We obtained several radial velocity curves for varying masses and distances that indicate a possible new planet, “says Satyal.
“The existence of this possible planet is supported by the long-term orbital stability of the system, orbital dynamics, and synthetic analysis of the radial velocity signal,” Satyal said. “At the same time, a significantly large number of radial velocity observations, transit method studies, as well as direct imaging are still needed to confirm the presence of possible new planets in the Gliese 832 system.”
Thus, if the new planet is around 1 Astronomical Unit from the star, it has a mass limit greater than 10 Earth masses and a generated radial velocity signal of 1.4 meters per second.
A planet with roughly the mass of Earth in the same place would have a radial velocity signal of only 0.14 m / s, thus much smaller and difficult to detect with current technology.
Let’s see what new data brings us new research.
Referencia: S. Satyal et al, Dynamics of a Probable Earth-mass Planet in the GJ 832 System, The Astrophysical Journal (2017). DOI: 10.3847/1538-4357/aa80e2
