Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2022 October 17
Explanation: 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-echoes to arrive.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell (UMCP)
NASA Official: Phillip Newman
Specific rights apply.
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GSFC,
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& Michigan Tech. U.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2022 October 18
It is possible that the stem of our Milky Way could bloom into a flower. It may appear that way in the featured all-sky image. The central plane of our home galaxy can be seen on the left. The sky's center is dominated by bright green-glowing oxygen on the right side of the picture. The two are not connected due to the fact that the red parts of the Aurora are in Earth's atmosphere. 10 trillion times further away, we can see the stars and nebulas of the Milky Way. The picture was taken across a small lake in northern Sweden. As our Sun's magnetic field develops into an active part of its 11-year cycle, it's likely that we'll see more Auroras near both of Earth's poles.
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Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell (UMCP)
NASA Official: Phillip Newman
Specific rights apply.
NASA Web
Privacy Policy and Important Notices
A service of:
ASD at
NASA /
GSFC,
NASA Science Activation
& Michigan Tech. U.