GRB 230307A was an exceptionally bright burst lasting ~200 seconds, which traditionally classified it as a long-duration core-collapse burst. However, follow-up observations with JWST detected a kilonova signature and the unmistakable spectroscopic fingerprint of tellurium (atomic mass 130), proving it originated from a neutron star merger that synthesized heavy r-process elements.
| Observatory / Instrument | Spectral Regime | Observational Detection & Counterpart Findings |
|---|---|---|
|
JWST (NIRCam / NIRSpec)
|
Infrared (1–5 µm)
|
Direct detection of 4.4 µm tellurium emission line, providing definitive proof of r-process nucleosynthesis.
|
|
Hubble Space Telescope
|
Optical (ACS)
|
Traced the runaway binary trajectory back to its original massive host spiral galaxy.
|
|
Chandra X-ray
|
X-ray
|
Identified fading X-ray counterpart at high galactic latitude.
|