Updated June 26, 2020, 5:23 p.m.
At least two super earths orbit one of the closest stars. Because of the short distance of eleven light years, this planetary system can be examined particularly well.
Researchers have discovered a planet system in a red dwarf star in our direct cosmic neighborhood. The star with catalog number GJ 887, only eleven light years away, is orbited by at least two planets from the super-earth class, possibly even three.
The team led by Sandra Jeffers from the University of Göttingen reports in the journal “Science”. Because of its short distance to one of the most investigated, the planetary system can be examined, the scientists believe.
Planets are usually outshone by home stars
Red dwarfs are the most common type of star in our home galaxy, the Milky Way. Most of them probably have Planets. The next planet outside our solar system also orbits a red dwarf, Proxima Centauri, 4.2 light years away.
GJ 887 is the twelfth nearest star to the sun. Jeffers’ team observed him every night for three months and combined this data with archived observation data from almost 20 years.
The analysis showed that the red dwarf fluctuates slightly, sometimes moving towards the observer and sometimes away from it. The cause of this wobble are the planets, which pull at the star with their gravity during their orbit.
In this way, numerous planets have already given themselves away. There is hardly a planet directly observable outside of our solar system, they are usually outshone by their home star.
Super earths too hot for life
The two confirmed planets are heavier than Earth, but lighter than Uranus, the smallest gas planet in our system. They therefore fall into the super earth category.
Both circle the Red Dwarf at a short distance, one in around 9 days, the other in just under 22 days. They get about two and a half times or eight times as much energy from their star as the earth from the sun. According to model calculations, it is an average of 80 or almost 200 degrees Celsius warm on them – too hot for life.
In the data, however, there are indications of a third planet with an orbital period of around 50 days. This would be in the so-called habitable zone around the red dwarf, where moderate temperatures prevail and the existence of liquid water is possible.
Red dwarf offers stable conditions
Liquid water is a basic requirement for life as we know it. If the existence of this third planet is confirmed, it could be an interesting target for the search for extraterrestrial life. Because for a red dwarf, GJ 887 is a remarkably calm star that offers stable conditions.
The researchers also emphasize that the short distance enables the next generation of space telescopes to be used to study possible planets’ atmospheres in this system.
The “James Webb” space telescope, for example, which is due to launch in the coming year, could recognize the signatures of gases such as carbon dioxide in the starlight reflected by the planets.
© dpa
A team of researchers has confirmed the existence of the earth-like exoplanet Proxima b. It orbits the star Proxima Centauri closest to our sun – and could house life and water.
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