Superluminous supernova

A superluminous supernova (SLSN, plural superluminous supernovae or SLSNe), also known as a hypernova, is a type of stellar explosion with a luminosity 10 or more times higher than that of standard supernovae. Like supernova, SLSNe seem to be produced by several different mechanisms, which is readily revealed by their light-curves and spectra. There are multiple models for what conditions may produce an SLSN, including core collapse in particularly massive stars, millisecond magnetars, interaction with circumstellar material (CSM model), or pair-instability supernovae.

Hypernovas produce long gamma ray bursts (GRBs), which range from 2 seconds to over a minute in duration.

GRBs were initially detected on July 2, 1967 by U.S. military satellites in high orbit, which were meant to detect gamma radiation. The United States had suspected the USSR of conducting secret nuclear tests despite signing the Nuclear Test Ban Treaty of 1963, and the Vela satellites were capable of detecting explosions behind the moon. The satellites detected a signal, but it was unlike that of a nuclear weapon signature, nor could it be correlated to solar flares.

Over the next few decades, the GRBs posed a compelling mystery. Gamma rays require highly energetic events to produce, yet GRBs could not be correlated to supernova, solar flares, or any other activity in the sky. Their brevity made them difficult to trace, but once their their direction could be determined, it was found that they were evenly spread out across the sky. This meant they were not originating in the Milky Way or nearby galaxies, but from deep space.

In February 1997, Dutch-Italian satellite BeppoSAX was able to trace GRB 970508 to a faint galaxy roughly 6 billion light years away. From analyzing the spectroscopic data for both the burst and the galaxy, Bloom et al concluded that a hypernova was the likely cause. That same year, hypernovae were hypothesized in greater detail by Princston astronomer Bohdan Paczyński

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