The Southern Ring Nebula Clock

The Southern Ring Nebula in near-infrared light, captured from the James Webb Space Telescope. This scene was created by a white dwarf star - the remains of a star like our Sun after it shed its outer layers and stopped burning fuel though nuclear fusion. Those outer layers now form the ejected shells all along this view. In this Near-Infrared Camera (NIRCam) image, the white dwarf appears to the lower left of the bright, central star, partially hidden by a diffraction spike. The same star appears - but brighter, larger, and redder - in the Mid-Infrared Instrument (MIRI) image. This white dwarf star is cloaked in thick layers of dust, which make it appear larger. Over thousands of years and before it became a white dwarf, the star periodically ejected mass - the visible shells of material. As if on repeat, it contracted, heated up - and then, unable to push out more material, pulsated. Stellar material was sent in all directions, and provided the ingredients for this asymmetrical la