Mysterious scar left by 2 stars 4.5 mn years ago found in space

Astronomers have discovered a mysterious scar in space that preserves an ancient encounter. Two massive stars, Beta and Epsilon Canis Majoris, passed near the Solar System about 4.5 million years ago, leaving a visible imprint in surrounding gas. Then younger and hotter, their intense ultraviolet radiation stripped surrounding gas, leaving a lasting mark that remains detectable even today.