The final high of a dying supermassive star

The model is an artist's illustration of a long **Gamma-ray burst (GRB)**, a sudden, very energetic explosion visible in gamma rays. These transient events are classified as *short* or *long*, depending on the duration of the burst. According to current knowledge, short GRBs originate from colliding neutron stars, long ones (such as the one represented in the model) from very energetic supernova explosions of supermassive stars (e.g. Wolf-Rayet stars such as *Eta Carinae*), which collapse into black holes or magnetars. The model shows the moment when relativistic jets from the just born black hole or magnetar break through the stellar surface and radiate as gamma rays. In these events, the explosion is highly focused with most of the energy collimated in the narrow jet / counter jet. For this reason, a GRB can only be detected when the collimated burst is pointed towards the Earth, so that the relatively narrow beam makes the burst appear as a very bright transient gamma-ray source.