German researchers have developed a new laser technique that will allow find Earth-like planets in distant space with unprecedented accuracy and ease.
KInown as laser frequency comb (LFC), the new technology was developed by the Max Planck Institute of Quantum Optics, the Kiepenheuer Institute for Solar Physics and the University Observatory Munich, Menlo Systems GmbH (Germany), the IAC and the Universidade Federal do Rio Grande do Norte (Brazil).
It is considered one of the most successful methods for finding planets around other stars by measuring the planet’s effect on the star’s motion by looking for tiny shifts in the parent star’s spectral lines due to the Doppler effect, explain researchers.
The LFC offers a source that is more stable than any method available before and the measurements of velocities can be calculated down to the level of only centimetres per second now, they add.
“If an observer elsewhere in the Galaxy wanted to detect the presence of the Earth as it orbits the Sun, they would have to measure the wobble of the Sun backwards and forwards over one year with equipment that was sensitive enough to pick up velocity changes with an amplitude of just 9 centimetres per second,” they explained.
It means the use of frequency combs will make possible the detection of Earth-mass planets in the habitable zones around nearby stars by the radial velocity technique. Such planets are among the best candidates for bearing life outside the Solar Syste, they said.
“An important aspect of our work is that we use a single-mode fibre which takes advantage of the wave nature of light to enable a very clean and stable beam at its output,” explained lead author Rafael Probst from the Max Planck Institute of Quantum Optics.
The results show that if the LFC light and the sunlight are simultaneously fed through the same single-mode fibre, the obtained calibration precision improves by about a factor of 100 over a temporally separated fibre transmission.
“We then obtain a calibration precision that keeps up with the best calibration precision ever obtained on an astrophysical spectrograph, and we even see considerable potential for further improvement,” Probst added.
The researchers hope to use the new technique to study the Sun and to find Earth-like planets that may be orbiting around the distant solar planets.
“It is expected the technique will allow a spectral analysis of distant stars with unprecedented accuracy, as well as advance research in other areas of astrophysics,” the authors concluded.
The paper has been published in the New Journal of Physics.