Astronomers find a planet through a never-before-used method

Astronomers have used a novel technique to discover an exoplanet by observing its orbital motion. KIC 7917485b is the first planet to be identified around a Type-A main sequence star from its orbital motion and the first to be found near that type of star’s “habitable zone”. Type-A stars are bigger and hotter than most other stars in the Kepler catalogue and tend to change brightness at regular intervals. By measuring apparent delays in that interval scientists can calculate the apparent oscillations of the star’s orbital motion which would be due to the gravitational effects of a nearby planet.