A new discovery has concluded that some massive stars can die silently, without ever exploding completely. This was thanks to the Einstein Probe, equipped with two next-generation, highly sensitive, wide-field X-ray instruments. Through a coordinated campaign involving optical and infrared telescopes, scientists confirmed that the event, cataloged as EP 250108a, was linked to a broad-line type Ic supernova, a rare type of stellar explosion.
It came from a considerable cosmic distance: 2.8 billion light-years
Its signal lasted only a few minutes, but it came from a considerable cosmic distance: 2.8 billion light-years. What was most intriguing was its intensity and brevity, a typical signature of what specialists refer to as FXTs. The nature of these flashes remains a mystery, although they continue to be analyzed thanks to the Einstein Probe, designed to capture brief X-ray events with a long range.
This was announced in Astronomy Magazine: “Long gamma-ray bursts (GRBs) are believed to originate from core collapse of massive stars. High-redshift GRBs can probe the star formation and reionization history of the early Universe, but their detection remains rare. Here we report the detection of a GRB triggered in the 0.5–4 keV band by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated as EP240315a, whose bright peak was also detected by the Swift Burst Alert Telescope and Konus-Wind through off-line analyses”.
Gemini North and South, SOAR in Chile, and later the James Webb Space Telescope
Other telescopes confirmed this data. Once the flash was detected, an international network of telescopes was mobilized to monitor the phenomenon’s evolution. Gemini North and South, SOAR in Chile, and later the James Webb Space Telescope (JWST), confirmed the burst and the extent of the light.
The case of this star is particularly striking because it is the closest FXT ever detected. Moreover, its signal was followed by the emergence of a visible supernova, called SN 2025kg. This direct relationship between an FXT and a supernova had never been documented in this way. The observations suggest that, rather than a violent explosion like those associated with gamma-ray bursts (GRBs), what occurred was a collapse with jets that failed to escape from the star’s interior.
To detect high-energy flashes of cataclysmic cosmic events, including tidal disruption events
And we return to the Einstein Probe, led by the Chinese Academy of Sciences (CAS) and launched on January 9, 2024. The goal? To detect high-energy flashes of cataclysmic cosmic events, including tidal disruption events or TDEs (stars pulled apart by supermassive black holes), supernovae, neutron stars and black holes, and high-energy electromagnetic counterparts of gravitational wave events.
The EP, therefore, has the potential to redefine the detection of cosmic explosions. Its ability to provide early warnings and coordinate international observations positions it as a key tool for future discoveries. The early detection of soft X-rays before gamma rays and the detailed analysis of their spectra not only confirm the value of the Probe but also raise new questions about the mechanisms behind stellar explosions.
This discovery would change the way we understand the end of life of massive stars
The data collected suggest that at least a small but significant percentage of type Ic-BL supernovae exhibit this type of X-ray signal, which could have gone undetected in the past due to the lack of appropriate instruments. This discovery would change the way we understand the end of life of massive stars.
This type of discovery highlights the importance of promoting research. None of this would be possible if states (and private companies) didn’t invest in education, research, and innovation. The universe is an immensity that cannot even be calculated, so every small discovery is a great scientific step forward.
