A bright gamma-ray flare interpreted as a giant magnetar flare in NGC 253

Understand

Magnetars are young, highly magnetized neutron stars that produce extremely rare giant flares of gamma-rays, the most luminous astrophysical phenomena in our Galaxy.

• The detection of these flares from outside the Local Group of galaxies has been predicted, with just two candidates so far.
• Here we report on the extremely bright gamma-ray flare GRB 200415A of April 15, 2020, which we localize, using the Interplanetary Network, to a tiny (20 sq.
• arcmin) area on the celestial sphere, that overlaps the central region of the Sculptor galaxy at 3.5 Mpc from the Milky Way.