GRB 230307A

230307A is the second brightest gamma ray burst detected in more than 50 years of observations and is located behind the Magellanic Bridge. Despite its long duration, it is most likely the result of the compact merger of a binary ejected from a galaxy in the local universe (redshift z=0.065).

Discovery

At 15:44:06 UT on 7 Mar 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230307A . at the same time, the Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor light curve shows a roughly fast rise and exponential decay (FRED) shape with a possible precursor, with a total duration of ~100 sec. At 2023-03-07T15:44:09Z UT (Solar Orbiter onboard time), Spectrometer Telescope for Imaging X-rays (STIX) detected GRB 230307A. The gamma-ray burst signal can be clearly seen in the STIX quick-look light curves in the range between 10 - 84 keV. The GRB has a single peak and a duration of about 40 seconds. The AGILE team also reported hours, T0 =15:44:06 (UTC) The event lasted about 30 s and it released a total number of 527069 counts in the MCAL detector (above a background rate of 1154 Hz), and 920952 counts in the AC Top detector (above a background rate of 2959 Hz). The 2001 Mars Odyssey's Gamma Ray Spectrometer on Mars also reported it within 12 hours resulting in precisely estimating its incoming direction through Interplanetary Network triangulation. Tellurium (Te) in GRB 230307A was discovered in 2023 by using the James Webb's Space Telescope's (JWST) mid infrared data. JWST obtained mid-infrared (mid-IR) imaging and spectroscopy 29 and 61 days after the burst.