At the center of the cosmic object, dubbed SBW1, is a star that was originally 20 times more massive than our sun and is now encased in a swirling ring of purple gas, the remains of a distant time when it cast off its outer layers via violent pulsations and winds.
Twenty-six years ago, NASA scientists say, another star with striking similarities to SBW1 went supernova. Early Hubble images of that star, SN 1987A, show eerie similarities to SBW1; both had rings of the same size and age and traveling at similar speeds; both were located in similar regions rich in ionized hydrogen; and they had the same brightness.
SBW1 is a snapshot of SN1987A's appearance before it exploded, say astronomers who have spent years studying both.
At more than 20,000 light years from Earth, SBW1 will be safe to observe, they said, and if we are lucky it could happen in our lifetimes.