A peer-reviewed study published September 16, 2026, identifies Elias 2-24 b as the youngest exoplanet discovered through direct high-contrast imaging. Researchers estimate that it is no more than about 1 million years old, based on the adopted age of its host system, Elias 2-24.
How astronomers confirmed the planet
Elias 2-24 b lies in a gap in the protoplanetary disk around Elias 2-24, about 55 astronomical units (au) from its star. A vortex coronagraph on the Keck telescope blocks much of a star’s glare, making it easier to detect faint objects nearby. Researchers reanalyzed Keck/NIRC2 observations from June 21, 2018, and June 1, 2020; the later observation recovered the object at a position compatible with the earlier one.
The team combined multiple image reductions, repeated recovery tests, tests using simulated companions and analysis of the source’s motion across the two epochs. That motion helped assess whether the faint point of light was associated with Elias 2-24 rather than a background object. The detection in each individual epoch fell below the conventional 5σ significance threshold, so the identification rests on the combined analyses, not on a single image.
How young is Elias 2-24 b?
The planet’s estimated age comes from the age researchers adopted for the Elias 2-24 system. The study places the system at no more than about 1 million years old and estimates the planet to be similarly young. The prior directly detected young-planet record holders were four planets orbiting PDS 70 and WISPIT 2, each older than 5 million years.
| Planet or group | Estimated age |
| Elias 2-24 b | No more than about 1 million years, based on the adopted age of the Elias 2-24 system |
| Four planets around PDS 70 and WISPIT 2 | Older than 5 million years |
Elias 2-24 b’s projected separation from its star was measured at 54.9 ± 4.3 au in 2018. Its position in a disk gap, at a wide orbit around such a young star, makes the system a useful test case for theories of how quickly giant planets form.
What the result means for planet formation
The research team interprets Elias 2-24 b as evidence that core accretion—the growth of a solid planetary core followed by the gathering of gas—can produce a giant planet at roughly 50 au within no more than about 1 million years. That is an interpretation of the planet’s properties, not a directly observed sequence of its formation.
Preferred evolutionary models estimate a mass of 1.9–4.0 Jupiter masses. The researchers treat that range as an upper limit because those models omit the effects of accretion. The finding gives planet-formation models a case of a giant planet at a wide separation early in its system’s history.
