The TESS space telescope is designed to detect exoplanets using the transit method. But, as is often the case in astronomy, the device began to be used for additional tasks and managed to make a number of unplanned discoveries. For example, it observed Comet Virtanen and noticed a flare on Proxima Centauri. Recently one more item was added to this list – TESS managed to detect gamma-ray burst for the first time.
Gamma-ray bursts represent the brightest electromagnetic events in the universe. They can produce as much energy in just a few seconds as the Sun does in its entire lifetime. Astronomers associate gamma-ray bursts with events such as collapses of massive luminaries as well as mergers of supercompact objects.
The gamma-ray burst detected by TESS was observed on October 16, 2020. It was designated as GRB 191016A. Its maximum stellar magnitude was 15.1. This is about 10,000 times less than the faintest stars that can be seen in the sky with the naked eye. At first glance, the flash seems dim, but only until you consider the distance. According to astronomers’ calculations, the light from GRB 191016A took 11.7 billion years to reach Earth.
To the above, it is worth adding that most recorded gamma-ray bursts are even less bright. On average, they are 160 thousand times dimmer than the dimmest stars visible to the naked eye in the night sky.
