WASHINGTON, March 7 (UPI) -- A new laser "frequency comb" tool for measuring light could help take the search for Earth-like planets to a new level of precision, U.S. researchers say.
The comb, a tool to precisely record frequencies of light, has been used for the first time to calibrate measurements of starlight from stars other than the Sun, with results suggesting such combs will eventually improve the search for Earth-like planets, the National Institute of Standards and Technology reported Wednesday.
The NIST-developed comb has calibrated measurements of a light-analyzing instrument on a telescope in Texas recording starlight emitted by M dwarf stars, plentiful in Earth's part of the galaxy and thought to have orbiting planets suitable to life, researchers said.
To search for planets orbiting distant stars, astronomers look for periodic variations in the apparent colors of starlight over time that can be caused by the star wobbling from the gravitational pull of an orbiting planet
"The comb worked great," NIST physicist Scott Diddams said. "In a few days, it enabled measurement precision comparable to the very best achieved in the same wavelength range with much more established techniques -- and we hope the comb will do much better as the new technique is perfected."
More than 600 planets have been discovered using star wobble analysis but the wobbling effect is very subtle and hard to detect with conventional technology, something with which the laser comb can help, researchers said.