The new frequency comb allows the Hobby-Eberly Telescope to more precisely measure specific frequencies and detect minute variations in color. Photo by NIST
Feb. 20 (UPI) -- Scientists at the National Institute of Standards and Technology have designed a custom frequency comb to boost the precision of the Hobby-Eberly Telescope in Texas.
The new comb -- designed with the help of researchers at the University of Colorado and Penn State -- allows the telescope's spectrograph to more precisely measure light frequencies, or the color of light. The new ability will make it possible for Hobby-Eberly to observe exoplanet-orbiting M dwarf stars, which make up 70 percent of the stars in the Milky Way.
"The comb immediately allowed our Penn State colleagues to make measurements they could not otherwise make," institute fellow Scott Diddams said in a news release. "These improved tools should allow us to find habitable planets around the most ubiquitous stars in our galaxy."
Though stellar fusion produces white light, the light's frequencies or colors are changed as they pass through the atmosphere. Each star produces a spectral fingerprint, a unique combination of colors that can be measured by a spectrograph.
The push and pull of orbiting planets can cause a star's spectral signature to wobble. Astronomers can look for color oscillations in spectrographic observations to locate distant exoplanets.
Frequency combs help scientists properly calibrate spectrographic observations. To detect subtle wobbles, the calibration process must be especially precise.
The new electro-optic laser frequency comb works like a real comb, isolating precise color frequencies and monitoring for minute variations.
Scientists described the new comb this week in the journal Optica.
Most alien worlds are discovered by measuring color oscillations, or wobbles, but the variations of color produced by planets in the habitable zone of M dwarf stars are especially subtle, making them more difficult to detect. The new comb, which scientist installed last year, will make it easier to find Earth-like exoplanets circling sun-like stars.