The bright spot visible within its fuzzy host galaxy in the image above is the optical and infrared light from a superlative gamma-ray burst. Discovered in October 2022, GRB 221009A was the brightest gamma-ray burst ever observed by humans, and likely a once-in-ten-millennia event, earning it the nickname “the Brightest of All Time” or BOAT gamma-ray burst. This image shows the afterglow of this burst nearly a year after it exploded onto the scene. In a recent article, Huei Sears (Rutgers University) and collaborators analyzed Hubble and JWST observations made 185–345 days after the discovery of the burst. These observations captured the burst’s fading light and showed a distinct shift in the rate at which the light dimmed at around 50 days. This shift is evidence of powerful jets from the source of the burst. Sears’s team also discovered a blue component to the afterglow emission. This blue component may be due to the burst’s afterglow echoing off of dust in the host galaxy — if confirmed, this will mark the first time this feature has been detected. To learn more about what astronomers have discovered in the years since GRB 221009A was first spotted, be sure to check out the full research article linked below!
Citation
“Late-Time HST and JWST Observations of GRB 221009A: Evidence for a Break in the Light Curve at 50 Days,” Huei Sears et al 2025 ApJ 984 196. doi:10.3847/1538-4357/adc306