Carmenes instrument, which it was co-developed by the Institute of Astrophysics of Andalusia, the Higher Council for Scientific Research (IAA-Csic), and looking for extrasolar planets from the telescope 3,5 meters from the Calar Alto Observatory, Almeria, It has allowed to find two new planets around the star Teegarden, one of the closest known.
With masses similar to Earth, their temperatures may be mild enough for liquid water on the surface, according to the study published in the scientific journal Astronomy & Astrophysics’.
As it reported by the IAA-CSIC in a press release, at a distance of only 12,5 Light years, Teegarden's star is the closest star system to our number twenty four, and one of the smallest red dwarf stars known. Despite their proximity and due to its low brightness, Teegarden's star was not identified until 2003.
“We've been watching this star with Carmenes instrument since the beginning of this project three years ago, in order to measure their movement with high accuracy”, ha explained Mathias Zechmeister, postdoctoral researcher at the University of Göttingen (Germany) who heads the work.
The planets were found by Doppler technique, to detect small planets movement produced its star to rotate around it, within the framework of a project which intervened scientists at the University of Granada, city in which it is based the IAA-CSIC.
The search for Earth-like planets around sun-like stars is complex because the speeds are so small they can not be detected with current technology.
Hence, Carmenes, it can measure them with an accuracy of one meter per second, It focuses on red dwarfs (o enanas M), “smaller stars that provide the conditions for the existence of liquid water in nearby orbits and which itself can detect the movements of planets similar to ours”.
“Carmenes is the first high-precision spectrometer operating specifically designed to find planets using this advantage of the red dwarf”, He added Zechmeister. The temperature of the star is only Teegarden 2.600 degrees (almost half of 5.500 degrees from the Sun), is 1.500 times fainter and ten times less massive than the Sun..
As a result, radiates most of its energy in red wavelengths and infrared, making it an ideal target for Carmenes, simultaneously operating in the visible and infrared.
Doppler measurements star Teegarden showed the presence of at least two signals, now identified as the two new exoplanets, Teegarden star called b and c. Obtaining consistent detection required the collection of over two hundred measurements and, depending on the measured movement, researchers have deduced that the planet Teegarden b star is similar to the Earth's mass and completes one orbit around the star every 4,9 days a 2,5 percent of the Earth-Sun distance.
For his part, c Teegarden's star is similar to Earth in terms of mass, completes its orbit in 11,4 days and is situated a 4,5 percent of the Earth-Sun distance.
Since Teegarden star radiates much less energy than our Sun, temperatures on these planets “They should be smooth and could, in principle, liquid water on the surface, especially in the outermost planet, Teegarden star c”. This type of planets are the main target for future searches for life beyond our solar system.