The stars are so close that the white dwarf can steal matter from its companion, and this matter piles up and explodes on the white dwarf’s surface.
Earth’s highest, coldest, rarest clouds are back. How to see the eerie ‘noctilucent clouds’ this summer.
Look North as the stars appear in June and July to have a chance of seeing rare noctilucent (or ‘night-shining’) clouds with the naked eye.