A comet with a bright head and a faint tail running the border every three seconds.

The same masked conic-gradient technique as the shine border, but the gradient is shaped as a comet rather than a band: a faint 4% lead, the accent at 8%, a single bright surface stop at 9% for the head, then a fall back to the accent and out to transparent by 16%. A drop-shadow filter on the same accent gives the head a halo that the mask cannot, since the mask clips the gradient to the ring. The result reads as one object travelling the edge, which is livelier than the shine and correspondingly less suited to more than one element per view.