VOA科学技术2022--天文学家观测到有史以来最明亮的闪光

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Astronomers¹ Studying Effects of Brightest Light Burst Ever Seen

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 noted² by orbiting telescopes on Sunday. Scientists across the world are continuing to observe its effects.

Astrophysicist Brendan O'Connor spoke³ 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 affected⁴ 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 infrared⁵ 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 Observatory⁶, and the Wind spacecraft on Sunday.

1.9 billion-year-old movie

The burst came from the direction of the constellation⁷ 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 recording⁸ 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 wavelengths¹⁰. 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, platinum¹¹ and uranium. Astronomers will also be hunting for those heavy metals.

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 wavelength⁹ 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