The longest-lived stars in the cosmos may not survive for 101100 years after all. A new theoretical estimate places the effective upper bound far lower, at 1078 years for white dwarfs, suggesting that the universe’s final clean-up act could be driven by a mechanism once associated only with black holes.
The idea begins with Stephen Hawking’s 1975 argument that black holes are not perfectly black. Quantum effects near intense gravity allow radiation to leak away, so mass is lost extraordinarily slowly over time. For decades, that process was treated as a special consequence of the event horizon, the boundary beyond which nothing can return. The newer work from Radboud University pushes the concept outward, arguing that the horizon is not the whole story and that spacetime curvature itself can help produce a similar draining effect in other massive objects.
That shift matters because it expands the cast of doomed objects from black holes to stellar remnants more broadly. In the researchers’ earlier analysis, objects without an event horizon could still generate radiation through gravity and tidal effects in curved spacetime. In the follow-up calculations, the team asked a more practical question: if that framework is right, how long would evaporation take? Their answer recasts white dwarfs as the ultimate holdouts, with neutron stars and stellar black holes both decaying on the order of 1067 years. That parity is one of the study’s more striking outcomes, because intuition suggests black holes should vanish faster under stronger gravity. Instead, the authors argue that black holes partly slow their own demise by reabsorbing some of the radiation they produce. Michael Wondrak described the surprise succinctly: But black holes have no surface. They reabsorb some of their own radiation which inhibits the process.
The density of an object appears to do most of the long-term bookkeeping. In this picture, evaporation time depends less on whether an object is a black hole and more on how tightly its mass is packed. That makes white dwarfs, compact but less extreme than neutron stars, the slowest to disappear. It also turns a familiar story about exotic cosmic monsters into a broader statement about matter itself: under enough time, even apparently stable remnants are not permanent fixtures.
The researchers also extended the calculation into more ordinary territory, estimating about 1090 years for the Moon and even a human body to evaporate through the same Hawking-like process. Those figures are more illustrative than practical, since many other physical processes would intervene first. Still, the exercise reveals the conceptual reach of the model. If the mechanism truly follows from gravity and quantum fields rather than from horizons alone, then permanence becomes difficult to assign to anything macroscopic.
Heino Falcke framed the result with understatement: “So the ultimate end of the universe comes much sooner than expected, but fortunately it still takes a very long time.” The underlying paper, published in JCAP in 2025, does not turn cosmic history into a countdown so much as refine one of physics’ strangest questions. Hawking radiation was already a challenge to the notion that black holes only grow. Extending a Hawking-like loss process to stars, moons and other massive bodies makes the challenge deeper: not only black holes, but the architecture of the universe itself, may be temporary in a more literal sense than modern cosmology once assumed.
