The closest exoplanets provide scientists with the best opportunity to seek evidence of life outside the solar system. In a study by the University of Gottingen, a team of RedDots astronomers discovered a system of super-Earth planets orbiting the nearest star, Gliese 887, a very bright red dwarf. Super-Earths are planets whose mass is higher than that of the Earth, but significantly lower than the mass of local ice giants, Uranus and Neptune. Recently discovered super-earths are located near the habitable zone of the red dwarf, where water can exist in liquid form. The results were published in the journal Science.
A team of RedDots astronomers observed a red dwarf using a HARPS spectrograph at the European Southern Observatory in Chile. They used the technique of “Doppler oscillation”, which allows you to measure the tiny oscillations of stars caused by the gravitational attraction of the planets. Regular signals correspond to orbits of only 9.3 and 21.8 days, indicating two super-Earths – Gliese 887b and Gliese 887c. Both are larger than Earth, but moving very fast, much faster than Mercury. Scientists estimate the temperature of Gliese 887c at approximately 70°C.
Gliese 887 is one of the stars closest to the Sun at a distance of about 11 light years. It is much dimmer and about half the size of our Sun. This means that the habitable zone of Gliese 887 is much closer to the red dwarf than the distance from the Earth to the Sun.
The RedDots team discovered two more interesting facts about the Gliese 887.
The red dwarf has very few star spots, unlike our sun. If Gliese 887 was as active as our Sun, it is likely that a strong stellar wind is the process of the outflow of matter from stars into interstellar space, which can destroy the planet’s atmosphere. It seems that newly discovered planets can retain their atmospheres or have thicker atmospheres than the Earth. And that means potentially having life, even if the GJ887 receive more light than the Earth.
Another interesting feature discovered by the team is that the brightness of the Gliese 887 is almost constant. Therefore, it will be relatively easy to detect the atmosphere of the super-Earth system, which will make it the main target for the James Webb Space Telescope, the successor to the Hubble telescope.
“These planets will provide the best opportunity for more detailed research, including the search for life outside our solar system”.Sandra Jeffers, a doctor from the University of Gottingen and author of the research