Kilonova Fade-out

These two images taken on May 26 and July 16, 2020, show the fading light of a kilonova located in a distant galaxy. The kilonova appears as a spot to the upper left of the host galaxy. The glow is prominent in the May 26 image but fades in the July 16 image. The kilonova's peak brightness reaches up to 10,000 times that of a classical nova. A merger of two neutron stars—the source of the kilonova—is believed to have produced a magnetar, which has an extremely powerful magnetic field. The energy from that magnetar brightened the material ejected from the explosion, causing it to become unusually bright at infrared wavelengths of light. NASA, ESA, W. Fong (Northwestern University), T. Laskar (University of Bath, UK) and A. Pagan (STScI)