19 October 2022
Astronomers have observed the brightest burst of light ever seen, from an event that happened 2.4 billion light-years from Earth. A light year is about 9.4 trillion kilometers.
The scientists say the burst was probably caused when a black hole formed.
Gamma rays are among the most intense forms of electromagnetic radiation. The burst was first noted by orbiting telescopes on Sunday. Scientists across the world are continuing to observe its effects.
Astrophysicist Brendan O'Connor spoke to the French News Agency. He said gamma ray bursts that last hundreds of seconds, as this one did, are thought to be caused when massive stars explode. Such stars are about 30 times the size of the Sun.
The massive star explosion, called a supernova, results in a massive black hole. A disk of matter forms around the black hole as it falls inside the massive object. Energy is also expelled away from the black hole in a jet. The expelled energy moves at 99.99 percent the speed of light.
The gamma ray burst released photons carrying a record amount of energy. It affected longwave radio communications in Earth's ionosphere.
"It's really breaking records, both in the amount of photons, and the energy of the photons that are reaching us," said O'Connor. The scientist used infrared instruments on the Gemini South telescope in Chile to take new observations recently.
"Something this bright, this nearby, is really a once-in-a-century event," he added.
"Gamma ray bursts in general release the same amount of energy that our sun produces over its entire lifetime" in just a few seconds, he noted.
"And this event is the brightest gamma ray burst," O'Conner said.
The gamma ray burst was first found by telescopes including NASA's Fermi Gamma-ray Space Telescope, the Neil Gehrels Swift Observatory, and the Wind spacecraft on Sunday.
1.9 billion-year-old movie
The burst came from the direction of the constellation Sagitta and traveled an estimated 1.9 billion years to reach Earth. That is less than the current distance of its starting point because of the expansion of the universe.
Observing the event now is like watching a 1.9 billion-year-old recording of those events. Astronomers have the rare chance to learn more about black hole formation and other mysteries.
O'Connor works with the University of Maryland and George Washington University. He said he and others will continue watching for the expected signs of supernovas at different wavelengths. The researchers aim to confirm that their theory about the burst's beginnings is correct, and that the event obeys the laws of physics.
Supernova explosions are also predicted to be responsible for producing heavy elements such as gold, platinum and uranium. Astronomers will also be hunting for those heavy metals.
I'm Caty Weaver.
Agence France-Presse reported this story. Caty Weaver adapted it for VOA Learning English.
Words in This Story
black hole –n. the remnant of a massive star which has such powerful gravity that even light cannot escape
astrophysicist – n. a scientist who studies the physical and chemical properties and structure of stars and outer space objects
disk – n. a flat, round object
photon – n. a particle of light
ionosphere – n. a part of the atmosphere from 70 to 400 kilometers above the Earth in which the sun's radiation affects the transmission of radio waves
infrared – n. a wavelength of electromagnetic radiation that cannot be seen with the human eye
constellation – n. a group of start that form a shape in the sky and that has a name and often a story about it