400 billion times more powerful than the sun! The most intense optical ultraviolet flare in the universe "appears"

Using the Swift satellite ultraviolet optical telescope, an international team led by researchers Fan Yizhong and Jin Zhiping from the Purple Mountain Observatory of the Chinese Academy of Sciences confirmed that the most intense optical ultraviolet flare ever detected by humans, the gamma-ray burst GRB 220101A, has a radiation luminosity of about 40 billion times that of the sun, breaking the world record . On June 26, the relevant research results were published online in Nature Astronomy.

Gamma-ray bursts are the most violent explosions on a stellar scale in the universe. Their main radiation energy is concentrated in the soft gamma-ray band. Therefore, the soft gamma-ray radiation period is also called the transient radiation phase of the gamma-ray burst. After the transient radiation ends, people can often observe afterglow radiation that lasts for about several weeks or even years. The optical flare phenomenon at the end of the transient radiation is considered to mark the beginning of afterglow radiation. The transient optical radiation of the gamma-ray burst GRB 080319B has long held the world record for the most violent optical ultraviolet flare event in the universe.

On January 1, 2022, the Swift satellite detected a new burst, GRB 220101A, with a bright optical afterglow. Scientists quickly measured that the redshift value of this gamma-ray burst was 4.618, indicating that the detected optical radiation was redshifted ultraviolet photons, which had lost about 99% before reaching the earth, that is, its actual radiation flux was about 100 times the observed value.

The research results show that GRB 220101A is an extremely violent optical ultraviolet flare, with a radiation luminosity of about 40 billion times that of the sun, breaking the world record held by GRB 080319B for 14 years. According to calculations, the absolute magnitude of GRB 220101A reached -39.4, making it the only optical ultraviolet radiation source with an absolute magnitude brighter than -39 that humans have detected so far. The study of its optical radiation behavior also shows the diversity of the physical origins of ultra-bright optical ultraviolet bursts.