The gamma ray burster GRB 221009A makes it into two apods recently.

https://apod.nasa.gov/apod/ap221015.html

The first is just the standard blurb, with a nice gif video from the Fermi space telescope showing it brightening and then dulling..

One of the brightest gamma-ray bursts ever detected GRB 221009A is also close as far as gamma-ray bursts go, but still lies about 2 billion light-years away … Fermi’s Large Area Telescope recorded gamma-ray photons from the burst for more than 10 hours

https://apod.nasa.gov/apod/ap221017.html

The second is more interesting. It’s a new way of probing the dust density in our own Milky Way by tracking light echos of X-rays from GRB 221009A off the Milky Way as the signal comes in. The observing space telescope is “Swift”.

“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.”

We’ve seen light echos before, notably from the star v838 mon, and from Hanny’s Voorwerp. But this is the first time I’ve seen one in X-rays, and also the first time I’ve seen one where the light source and echo are 2 billion light years apart!