14 DAY TRIAL // Despite the fact that over 300 exoplanets have thus far been discovered, identifying celestial bodies the size of the Earth orbiting stars billions of light-years away is no easy task. The method currently used to identify such planets is one that undoubtedly yields results, but it's also very time-consuming and costly, so researchers at the Harvard-Smithsonian Center for Astrophysics, in Cambridge, Massachusetts, have created a new method, dubbed astro-comb, of analyzing distant light coming in from stars hundreds and thousands of parsecs away.
Usually, when it comes to discovering small exoplanets in a tight orbit around their stars, specialized telescopes simply peer at the solar systems, and wait for anomalies in the amount of light the star emits. Once they happen, there is a possibility that the disturbance be caused by a planet passing in front of its star. By assessing how much the light has diminished when the planet, moon, or asteroid moved in front of it, astronomers can determine the mass of that specific body. This complex identification procedure makes use of the basic principles of space spectroscopy.
At this point, the efficiency of spectroscopy can be assessed in a few meters per second, which is a very narrow margin for error, given the distance. However, the HSCA team say they've devised a system for watching far-away stars that is accurate to the level of one meter per second. At least in theory, this would allow Earth- and orbit-based observatories to better establish a few of the exoplanet's characteristics, such as speed, location, and so on. David Phillips, one of the team members, argues that the next generation of observatories will benefit from spectroscopy instruments that will allow them to detect shifts of less than 60 centimeters per second, or even one centimeter per second.
The astro-comb technique the HSCA team has devised relies on high-frequency lasers, which are able to emit radiation on not just one, but multiple wavelengths, at different intensities. Because the energy of the laser pulses is very well established, astronomers could use this technique to identify minuscule variations in the movements of a distant star, which may account for the existence of an exoplanet around it. The first large observatory where this system will be installed is the William Herschel Telescope, located on a mountaintop in the Canary Islands, ScienceDaily reports.