GRB 221009A: Discovery of an Exceptionally Rare Nearby and Energetic Gamma-Ray Burst

Understand

We report the discovery of the unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by the Neil Gehrels Swift Observatory (Swift), Monitor of All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER).

• This energetic GRB was located relatively nearby (z = 0.151), allowing for sustained observations of the afterglow.
• The large X-ray luminosity and low Galactic latitude (b = 4.3 degrees) make GRB 221009A a powerful probe of dust in the Milky Way.
• Using echo tomography we map the line-of-sight dust distribution and find evidence for significant column densities at large distances (~> 10kpc).