For five decades, gamma-ray bursts were divided into short (< 2s, mergers) and long (> 2s, massive star collapse). GRB 211211A completely overturned this dogma: lasting 51.4 seconds, its optical and near-infrared afterglow revealed an excess of luminosity caused by a kilonova fueled by radioactive decay of neutron-rich matter, proving a compact binary merger can produce minute-long gamma emission.
| Observatory / Instrument | Spectral Regime | Observational Detection & Counterpart Findings |
|---|---|---|
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HST & Nordic Optical Telescope
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Optical & NIR
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Identified excess thermal near-infrared emission matching kilonova models.
|
|
Swift XRT
|
X-ray
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Detected plateau phase pointing to sustained magnetar spin-down injection.
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