Photometry of Transiting Planet GJ 436b

This artist's diagram shows the unusual light curve produced when the exoplanet GJ 436b and the huge, comet-like hydrogen cloud nicknamed "The Behemoth" pass in front of the parent star. Because the planet's orbit is tilted nearly edge-on to our view from Earth, the planet and cloud can be seen eclipsing its star. Astronomers see the extended dip in the light caused by the enormous cloud. That dip trails off slowly due to the cloud's comet-like tail.