A team of astronomers, led by Trifon Trifonov of the Max-Planck-Institut für Astronomie (Germany), has discovered a hot rocky planet orbiting the red dwarf star Gliese 486 just 26 light-years away (Science, 4th of March).
Although the planet, designated Gliese 486b, is close to its parent star, it may have retained a remnant of its original atmosphere. This makes it an interesting research object for the next generation of telescopes on Earth and in space.
Over the past 25 years, astronomers have discovered thousands of planets around other stars. Only a small part of these ‘exoplanets’ have similarities with the Earth. This is what astronomers deduce from the masses, sizes and densities of these objects. However, virtually nothing is known about their possible atmospheres.
This also applies to the now discovered planet, which belongs to the “super-Earths.” Gliese 486b has almost three times the mass of our own planet and is thirty percent larger. This results in an average density comparable to that of Venus and the Earth.
The big difference from the latter planets is that Gliese 486b orbits its star at a distance of only 2.5 million kilometers, so that a year on the planet lasts only one and a half Earth days. Although that star is much cooler and less bright than our sun, this results in a surface temperature of about 430 ° C. In that respect, the planet is more like Venus than the Earth.
Calculations indicate that it may not have as dense an atmosphere as our neighborhood planet, but it may have a thinner atmosphere. However, to be sure of that, astronomers will have to be patient. For the necessary measurements, they depend on the Extreme Large Telescope of the European Southern Observatory in Chile and the JWST space telescope, which will be launched in October this year, still under construction. (EE)
A blazing nearby super-Earth –
