A team of astronomers has used the LCOGT network to detect light scattered by tiny particles — called Rayleigh scattering — through the atmosphere of a Neptune-sized transiting exoplanet.
This suggests a blue sky on this world that is only 100 light-years away from us.
Transits occur when an exoplanet passes in front of its parent star, reducing the amount of light we receive from the star by a small fraction. When the orbit of an exoplanet is aligned just right for transits to occur, astronomers can measure the planet’s size at different wavelengths in order to generate a spectrum of its atmosphere.
The spectrum then reveals the substances present in the planet’s atmosphere, and therefore its composition.