The First Stars in the Universe

Astronomers have long wondered about the nature of the first stars that formed in the universe. These stars were responsible for creating new chemical elements, enriching the cosmos, and paving the way for subsequent generations of stars to form the first planets.

The First Stars: Formation and Characteristics

The first stars were composed of pure hydrogen and helium and possessed massive sizes, reaching hundreds or even thousands of times the mass of the sun. These stars were incredibly luminous but had short lifespans, ending in colossal explosions known as supernovae. Due to their brief existence and lack of raw materials, they did not have the time or capacity to form planets.

Astronomers believe that these stars are no longer observable, as their lives ended long ago. However, recent studies suggest the possibility of lower-mass stars having formed in the early universe.

New Studies Reveal New Possibilities

Two studies published in the first half of 2025 propose that collapsing gas clouds in the early universe may have formed stars with lower masses. One study used new computer simulations to model disturbances within the cloud, leading to its fragmentation into smaller masses that formed stars.

The other study, an independent laboratory experiment, demonstrated how molecular hydrogen, a crucial molecule in star formation, could form earlier and in greater quantities than previously expected.

The Role of Chemistry in the Early Universe

Chemistry played a larger role than expected in the early universe. The interaction of molecular hydrogen with chemical variables helped cool the gas clouds, making them more susceptible to gravitational collapse and the formation of lower-mass stars.

In a study published in July 2025, a team of researchers showed that helium hydride, the first molecule to form in the universe, was more abundant than previously thought. This abundance helped cool the gas clouds more rapidly.

Challenges and the Future

Searching for lower-mass stars that may still exist in the universe is not easy. These stars are dim, making them difficult to detect. Nevertheless, astronomers continue their efforts to find them.

If scientists can discover these stars, it would provide new insights into star and planet formation in the early universe.

Conclusion

Recent studies reveal that the early universe was more complex than previously believed. Chemistry played a pivotal role in forming the first stars, and not all first stars may have been as massive as once thought. If research continues in this direction, we may be able to rewrite the history of the early universe and gain a deeper understanding of how stars and planets formed.