Astronomers have utilized data gathered from a network of space and terrestrial telescopes to identify AT 2024wpp, the most radiant blue light transient (LFBOT) ever recorded. These uncommon, ephemeral, and exceedingly luminous outbursts have perplexed scientists for a decade, but the extraordinary brightness and comprehensive multiwavelength data from AT 2024wpp indicate that they cannot be attributed to typical stellar explosions such as supernovae. Instead, recent observations reveal that AT 2024wpp was generated by an extreme tidal disruption event, where a black hole, with a mass approximately 100 times that of the Sun, dismantles a massive companion star over the course of just a few days, converting a significant portion of the star’s mass into energy.
This composite image contains X-ray and optical data for the LFBOT event at 2024wpp. Image credits: NASA / CXC / University of California, Berkeley / Nayana others. / Legacy Survey / DECaLS / BASS / MzLS / SAO / P. Edmonds / N. Walk.
LFBOTs derive their name from their intense brightness, being visible from hundreds of millions to billions of light years away, and their ephemeral nature, lasting merely a few days.
They emit high-energy light across the blue spectrum into ultraviolet and X-rays.
The inaugural observation was made in 2014, but the first LFBOT with sufficient data for analysis was recorded in 2018, termed AT 2018cow, in accordance with standard naming conventions.
Researchers nicknamed it “cow”, alongside other LFBOTs dubbed “tongue-twisted koala” (ZTF18abvkwla), “Tasmanian devil” (AT 2022tsd), and “finch” (AT 2023fhn). AT 2024wpp is likely to be known as Wasp.
Researchers determined that AT 2024wpp was not a supernova after assessing the energy output of the phenomenon.
The energy was found to be 100 times greater than that produced by typical supernovae.
The emitted energy must convert roughly 10% of the Sun’s rest mass into energy over a brief period of weeks.
Specifically, observations from Gemini South disclosed excess near-infrared radiation emitted by a luminous source.
This marks the second instance astronomers have witnessed such an occurrence, with the first being AT 2018cow, which seemingly doesn’t occur in regular stellar explosions.
These observations establish near-infrared excess as a defining characteristic of FBOT, yet no model can adequately explain it.
“The energy released by these bursts is so immense that it cannot be accounted for by a nuclear collapse or any typical stellar explosion,” stated Nathalie LeBaron, a graduate student at the University of California, Berkeley.
“The main takeaway from AT 2024wpp is that the model we initially proposed is incorrect. This is definitely not an ordinary exploding star.”
Scientists suggest that the intense high-energy light emitted during this extreme tidal disruption stems from the black hole binary system’s prolonged parasitic behavior.
As they piece together this history, it appears the black hole has been gradually siphoning material from its companion star, enveloping itself in a ring of material too distant to be consumed.
Subsequently, when the companion star ventured too near and was shredded, the new material became ensnared in a rotating accretion disk, colliding with pre-existing material and releasing X-rays, ultraviolet light, and blue radiation.
Much of the gas from the companion star ended up spiraling toward the black hole’s poles, where it was expelled as material jets.
Authors calculated that the jet was traveling at about 40% the speed of light and emitted radio waves upon interacting with surrounding gas.
Similar to most LFBOTs, AT 2024wpp is situated in a galaxy characterized by active star formation, making the presence of large stars likely.
Located 1.1 billion light years away, AT 2024wpp is 5 to 10 times more brilliant than AT 2018cow.
The companion star that was torn apart was estimated to be over 10 times the mass of the Sun.
“It may have been what is referred to as a Wolf-Rayet star, a very hot evolved star that has depleted much of its hydrogen,” remarked the astronomers.
“This would account for the weak hydrogen emission observed from AT 2024wpp.”
The findings are published in two papers: Astrophysics Journal Letter.
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Natalie LeBaron others. 2025. Brightest known fast blue light transient AT 2024wpp: unprecedented evolution and properties from ultraviolet to near-infrared. APJL in press. arXiv: 2509.00951
AJ Nayana others. 2025. Brightest known fast blue light transient AT 2024wpp: unprecedented evolution and properties in X-rays and radio. APJL in press. arXiv: 2509.00952
Source: www.sci.news
