Kyushu University Researchers Detect Cosmic Drift in Prestellar Cores for Star Formation Insights

On July 10, 2026, researchers from Kyushu University and the Max Planck Institute for Extraterrestrial Physics published a groundbreaking study in Astronomy & Astrophysics, revealing the detection of ambipolar diffusion in a prestellar core. This phenomenon may play a crucial role in the gravitational collapse that leads to star formation, providing new insights into how stars like our sun come into existence.

Understanding Prestellar Cores and Star Formation

Prestellar cores are dense and cold regions of gas and dust, where stars begin their formation journey. According to Doris Arzoumanian, the first author of the study, these cores are not only fascinating but also crucial for understanding complex chemical processes. "The cold environment allows molecules to assemble into more complex ones, like precursors of prebiotic organic molecules," she explained.

However, the presence of strong magnetic fields within these cores can inhibit gravitational collapse, delaying star formation. The research team aimed to uncover how these magnetic fields weaken over time, allowing for the birth of protostars.

Key Findings on Ambipolar Diffusion

The team focused on the prestellar core L1544, located in the Taurus molecular cloud, one of the closest active star-forming regions to Earth. Using the Institute for Radio Astronomy in the Millimeter Range (IRAM) 30-meter telescope, they identified two crucial molecules: Diazenylium-d¹ (N₂D⁺) and para-monodeuterated ammonia (para-NH₂D).

By analyzing the velocity of these molecules, the researchers observed a significant difference, approximately 0.05 km/s, indicating the presence of ion-neutral drift. As the prestellar core becomes denser, it shields itself from radiation, reducing ionization and allowing neutral particles to drift inward due to gravity.

The Implications for Star Formation Research

This process, known as ambipolar diffusion, is crucial as it decreases the strength of the magnetic field, ultimately leading to the gravitational collapse of the core into a protostar. Arzoumanian noted, "Observing this phenomenon in a prestellar core was a major challenge until now. As ambipolar diffusion continues, gravity becomes the primary force driving the core's collapse."

To further validate their findings, the team plans to study additional prestellar cores and acquire higher-angular-resolution observations, aiming for more detailed maps of the ion and neutral molecules' velocity drift.

• Key Findings:
• Detection of ambipolar diffusion in prestellar cores
• Study focused on L1544 in the Taurus molecular cloud
• Velocity difference of 0.05 km/s between ions and neutral molecules
• Research published in Astronomy & Astrophysics

Understanding these processes is vital for addressing fundamental questions about the origins of life in planetary systems and enhancing our comprehension of the universe.