Astronomers yesterday said they have identified the largest cosmic explosion ever observed, a fireball 100 times the size of the solar system that suddenly began blazing in a distant universe more than three years ago.
While the astronomers offered what they think is the most likely explanation for the explosion, they emphasized that more research was needed to understand the puzzling phenomenon.
However, the explosion, called AT2021lwx, was not the brightest flash ever observed in the universe. That record is still held by a gamma-ray burst in October last year that was nicknamed BOAT — for Brightest Of All Time.
Photo: AFP / Sheffield University / Mark A. GARLICK
Philip Wiseman, an astrophysicist at the University of Southampton in England and the lead author of a new study, said that AT2021lwx was considered the largest explosion because it had released far more energy over the past three years than was produced by BOAT’s brief flash.
Wiseman said it was an “accidental discovery.”
The Zwicky Transient Facility in California first spotted AT2021lwx during an automated sweep of the sky in 2020.
However, “it basically sat in a database” until being noticed by scientists the following year, Wiseman said.
It was only when astronomers, including Wiseman, looked at it through more powerful telescopes that they realized what they had on their hands.
By analysing different wavelengths of light, they worked out that the explosion was about 8 billion light years away.
That is much farther away than most other new flashes of light in the sky — which means the explosion behind it must have been far greater.
AT2021lwx was estimated to be about 2 trillion times brighter than the sun, Wiseman said.
Astronomers have looked into several possible explanations.
One is that AT2021lwx is an exploding star — but the flash is 10 times brighter than any previously seen supernova.
Another possibility is what is called a tidal disruption event, when a star is torn apart as it is sucked into a supermassive black hole.
However, AT2021lwx is still three times brighter than those events, and Wiseman said the research did not point in this direction.
The only somewhat comparable bright cosmic event is a quasar, when supermassive black holes swallow huge amounts of gas in the center of galaxies.
However, they tend to flicker in brightness, whereas AT2021lwx suddenly started flaring up from nothing three years ago, and it is still blazing away, Wiseman said
“This thing we have never, ever seen before — it just came out of nowhere,” Wiseman said.
In the new study, published in the Monthly Notices of the Royal Astronomical Society, the international team of researchers laid out what they believe is the most likely scenario.
Their theory is that a massive, single cloud of gas — about 5,000 times larger than the sun — is slowly being consumed by a supermassive black hole.
Wiseman said that “in science, there’s never certainty.”
The astronomers are working on new simulations to see if their theory is “fully plausible,” he added.
One problem could be that supermassive black holes sit in the center of galaxies — for an explosion this size, the galaxy would be expected to be as vast as the Milky Way, Wiseman said.
However, no one has been able to spot a galaxy in the vicinity of AT2021lwx.
“That’s an absolute puzzle,” Wiseman said.
Now that astronomers know what to look for, they are searching the skies to see if other similar explosions have been missed.
A beauty queen who pulled out of the Miss South Africa competition when her nationality was questioned has said she wants to relocate to Nigeria, after coming second in the Miss Universe pageant while representing the West African country. Chidimma Adetshina, whose father is Nigerian, was crowned Miss Universe Africa and Oceania and was runner-up to Denmark’s Victoria Kjar Theilvig in Mexico on Saturday night. The 23-year-old law student withdrew from the Miss South Africa competition in August, saying that she needed to protect herself and her family after the government alleged that her mother had stolen the identity of a South
BELT-TIGHTENING: Chinese investments in Cambodia are projected to drop to US$35 million in 2026 from more than US$420 million in 2021 At a ceremony in August, Cambodian Prime Minister Hun Manet knelt to receive blessings from saffron-robed monks as fireworks and balloons heralded the breaking of ground for a canal he hoped would transform his country’s economic fortunes. Addressing hundreds of people waving the Cambodian flag, Hun Manet said China would contribute 49 percent to the funding of the Funan Techo Canal that would link the Mekong River to the Gulf of Thailand and reduce Cambodia’s shipping reliance on Vietnam. Cambodia’s government estimates the strategic, if contentious, infrastructure project would cost US$1.7 billion, nearly 4 percent of the nation’s annual GDP. However, months later,
HOPEFUL FOR PEACE: Zelenskiy said that the war would ‘end sooner’ with Trump and that Ukraine must do all it can to ensure the fighting ends next year Russia’s state-owned gas company Gazprom early yesterday suspended gas deliveries via Ukraine, Vienna-based utility OMV said, in a development that signals a fast-approaching end of Moscow’s last gas flows to Europe. Russia’s oldest gas-export route to Europe, a pipeline dating back to Soviet days via Ukraine, is set to shut at the end of this year. Ukraine has said it would not extend the transit agreement with Russian state-owned Gazprom to deprive Russia of profits that Kyiv says help to finance the war against it. Moscow’s suspension of gas for Austria, the main receiver of gas via Ukraine, means Russia now only
‘HARD-HEADED’: Some people did not evacuate to protect their property or because they were skeptical of the warnings, a disaster agency official said Typhoon Man-yi yesterday slammed into the Philippines’ most populous island, with the national weather service warning of flooding, landslides and huge waves as the storm sweeps across the archipelago nation. Man-yi was still packing maximum sustained winds of 185kph after making its first landfall late on Saturday on lightly populated Catanduanes island. More than 1.2 million people fled their homes ahead of Man-yi as the weather forecaster warned of a “life-threatening” effect from the powerful storm, which follows an unusual streak of violent weather. Man-yi uprooted trees, brought down power lines and smashed flimsy houses to pieces after hitting Catanduanes in the typhoon-prone
RSS