Flagstaff, AZ.– Astronomers at Yale University, in collaboration with Lowell Observatory, are embarking on a search that will answer one of the oldest questions in astronomy: Are there planets similar to Earth orbiting other stars?
Lowell Observatory’s Discovery Channel Telescope will gather light from stars and feed it into the Extreme Precision Spectrometer (EXPRES). A spectrometer splits light into different colors, similar to how shining light through a prism produces a rainbow. Astronomers will then analyze the light to search for the signatures of a planet. In this case, a change in the motion of the star along our line of sight –the radial velocity–, would indicate the presence of a planet.
The gravity of a star pulls the planet (or planets) towards it, but the planet does not fall into the star because of its circular motion. At the same time, the planet is actually pulling the star back. Big planets will give a big pull, causing a larger change in the radial velocity of the host star. The pull produced by small planets is very difficult to measure.
“Up until now the only planets we could detect with ground-based spectrometers were the bigger ones, the Saturns and Jupiters,” ...