Andrea Bernardi led a team at Diego Portales University in Chile that identified Elias 2-24b as the youngest known exoplanets discovery ever. The planet sits in a gap around Elias 2-24, where astronomers had tracked a possible object for nearly a decade.
The team compared observations from 2018 and 2020 taken at the W.M. Keck Observatory in Hawaii. That time gap let researchers test whether the bright spot moved with Elias 2-24, and they concluded it was gravitationally bound to the star.
Elias 2-24b and the gap
The work focused on seven protoplanetary disks with notable gaps. In the case of Elias 2-24, the European Southern Observatory’s Very Large Telescope had already detected a point of light inside the gap, but the new analysis tied the object to the star rather than treating it as a background source.
Elias 2-24b lies about 450 light-years from Earth and orbits at about 55 astronomical units. Its mass is estimated to be at most 1.9 to 4.0 times that of Jupiter, and the host star Elias 2-24 is less than 1 million years old.
PDS 70 and WISPIT 2
The record matters because most of the approximately 6,000 exoplanets confirmed to date are billions of years old. Before this result, the youngest directly observed exoplanets were those orbiting PDS 70 and WISPIT 2, and both systems are over 5 million years old.
NASA says it should take about 5 million years for a Jupiter-sized planet to form under the core accretion model. Elias 2-24b is younger than that benchmark, giving astronomers a rare view of planet formation at an earlier stage than the previous record holders.
Andrea Bernardi at Diego Portales University
Bernardi’s group used existing observations rather than a new search for a different class of planet. By comparing the object's position over time, the researchers narrowed the question from “is there a light source in the gap?” to “is that source part of Elias 2-24?”
The remaining open point is physical scale: how much smaller Elias 2-24b’s volume is than Jupiter’s is not specified. What the current analysis does show is that Elias 2-24b now sets the age mark other directly observed exoplanets are measured against.
