X-Ray Rings Around a Gamma Ray Burst

Why would x-ray rings appear around a gamma-ray burst? The surprising answer has little to do with the explosion itself but rather with light reflected off areas of dust -laden gas in our own Milky Way Galaxy . GRB 221009A was a tremendous explosion -- a very bright gamma-ray burst (GRB) that occurred far across the universe with radiation just arriving in our Solar System last week. Since GRBs can also emit copious amounts of x-rays , a bright flash of x-rays arrived nearly simultaneously with the gamma-radiation . In this case , the X-rays also bounced off regions high in dust right here in our Milky Way Galaxy , creating the unusual reflections . The greater the angle between reflecting Milky Way dust and the GRB, the greater the radius of the X-ray rings , and, typically, the longer it takes for these light-echoe s to arrive.