Leveraging an array of celestial observation instruments, both from Earth and in orbit, astrophysicists have identified AT 2024wpp, heretofore the most radiant fast blue optical transient (LFBOT) ever documented. These exceedingly rare, transient, and intensely incandescent cosmic events have perplexed the scientific community for a decade. However, the exceptional luminosity and comprehensive multiwavelength data associated with AT 2024wpp preclude explanations rooted in conventional stellar cataclysms, such as supernovae. Instead, current findings suggest that AT 2024wpp originated from an extreme tidal disruption event. In this scenario, a stellar-mass black hole, estimated to be up to approximately 100 solar masses, violently disintegrated a substantial companion star within a span of days, transforming an extraordinary proportion of the star’s mass into energy.
This composite image features X-ray and optical data of the LFBOT event AT 2024wpp. Image credit: NASA / CXC / UC Berkeley / Nayana et al. / Legacy Survey / DECaLS / BASS / MzLS / SAO / P. Edmonds / N. Wolk.
LFBOTs derive their nomenclature from their remarkable brilliance, making them observable across vast cosmological distances ranging from hundreds of millions to billions of light-years, and their ephemeral existence, lasting merely a few days.
These phenomena are characterized by the emission of high-energy electromagnetic radiation, spanning the blue portion of the visible spectrum through ultraviolet and X-ray wavelengths.
The inaugural observation of such an event occurred in 2014. However, the first instance with sufficient observational detail for rigorous analysis was recorded in 2018 and, adhering to standard astronomical naming conventions, was designated AT 2018cow.
This appellation led researchers to colloquially refer to it as “the Cow.” Subsequently, other LFBOTs have been playfully christened, such as “the Koala” (ZTF18abvkwla), “the Tasmanian devil” (AT 2022tsd), and “the Finch” (AT 2023fhn). It is conceivable that AT 2024wpp might colloquially become known as “the Wasp.”
The conclusion that AT 2024wpp could not be attributed to a supernova emerged after the research team meticulously computed the energy output of the event.
The calculated energy release was found to be 100 times greater than that generated by a typical supernova event.
The prodigious amount of radiated energy would necessitate the conversion of approximately 10% of the Sun’s rest-mass into energy within an exceedingly compressed timeframe of mere weeks.
Specifically, observations conducted with the Gemini South telescope indicated an anomalous emission of near-infrared light emanating from the source.
This constitutes only the second documented instance of such a phenomenon being observed by astronomers; the prior occurrence being AT 2018cow. This characteristic is demonstrably absent in the emissions from conventional stellar explosions.
These observational findings serve to establish the near-infrared excess as a defining signature of FBOTs, although no current theoretical model adequately accounts for its presence.
“The sheer magnitude of energy radiated from these transient bursts is so immense that it cannot be accounted for by a core-collapse stellar explosion or any other variety of standard stellar explosion,” stated Natalie LeBaron, a doctoral candidate at the University of California, Berkeley.
“The paramount takeaway from AT 2024wpp is that our initial theoretical framework is fundamentally flawed. It is unequivocally not merely a stellar explosion.”
The scientific hypothesis posits that the intense, high-energy radiation observed during this extreme tidal disruption event was a consequence of the protracted parasitic existence of the black hole within a binary stellar system.
As they meticulously reconstruct this celestial history, it is inferred that the black hole had been continuously accreting material from its companion star over an extended period. This process led to the formation of an extensive halo of matter surrounding the black hole, situated beyond its immediate gravitational grasp.
Subsequently, when the companion star ventured too close and was ultimately dismembered, the infalling material was incorporated into the rotating accretion disk and violently collided with the pre-existing matter, thereby generating X-ray, ultraviolet, and blue light emissions.
A significant portion of the gas originating from the companion star was also propelled towards the black hole’s poles, where it was subsequently expelled in the form of a relativistic jet.
The researchers calculated that these jets were propagating at approximately 40% of the speed of light and produced radio waves upon interacting with the ambient interstellar gas.
In alignment with the majority of LFBOT occurrences, AT 2024wpp is situated within a galaxy exhibiting vigorous star formation, a milieu where the existence of massive stars is to be anticipated.
AT 2024wpp is located 1.1 billion light-years distant and exhibits a luminosity between 5 and 10 times greater than that of AT 2018cow.
The estimated mass of the companion star that was subjected to tidal disruption exceeded 10 times the mass of the Sun.
“It may have been a celestial body known as a Wolf-Rayet star, which is characterized as a highly energetic and evolved star that has already depleted a substantial portion of its hydrogen fuel,” the astronomers elucidated.
“This characteristic would satisfactorily account for the attenuated hydrogen emission observed from AT 2024wpp.”
The findings derived from these investigations are presented in two distinct scholarly publications within the Astrophysical Journal Letters.
_____
Natalie LeBaron et al. 2025. The Most Luminous Known Fast Blue Optical Transient AT 2024wpp: Unprecedented Evolution and Properties in the Ultraviolet to the Near-Infrared. ApJL, in press; arXiv: 2509.00951
A.J. Nayana et al. 2025. The Most Luminous Known Fast Blue Optical Transient AT 2024wpp: Unprecedented Evolution and Properties in the X-rays and Radio. ApJL, in press; arXiv: 2509.00952
