Which planets have aurooras been observed on ?
According to the main author of the paper in " Nature " which announced the discovery of the two planets , Stephane Charpinet , the two planets " probably plunged deep into the star ’s envelope during the red giant phase , but survived . ” However , this is not the first sighting of planets orbiting a post-red giant star - numerous pulsar planets have been observed , but no planet has been found with such a short period around any star , whether or not on the main sequence .