New Technique to Weigh Planets

Although there have been about 800 extra-solar planets discovered so far in our galaxy, the precise masses of the majority of them are still unknown, as the most-common planet-finding technique provides only a general idea of an object’s mass. Previously, the only way to determine a planet’s exact mass was if it transits -- has an orbit that periodically eclipses that of its host star. Former Carnegie scientist Mercedes López-Morales has, for the first time, determined the mass of a non-transiting planet. The work is published by Astrophysical Journal Letters.