New Delhi: In a major breakthrough in astronomy, Indian researchers have identified one of the shortest-period stellar binary systems ever discovered, marking the world’s first confirmed finding of a blue straggler star accompanied by a brown dwarf companion in an extremely compact orbit.
The discovery was made by scientists from Gauhati University, Indian Institute of Astrophysics, Aryabhatta Research Institute of Observational Sciences and Italy’s INAF-Catania Astrophysical Observatory.
Researchers said the newly identified system has an orbital period of just 5.6 hours, making it one of the most compact binary systems ever observed. The companion object is a brown dwarf — a celestial body too massive to be classified as a planet but too small to sustain hydrogen fusion like a normal star.
The study revealed that the brown dwarf has a mass nearly 0.056 times that of the Sun, placing it below the hydrogen-burning limit. Scientists described it as the lightest companion ever detected around a blue straggler star.
Blue straggler stars have long puzzled astronomers because they appear brighter and younger than other stars in the same cluster, despite all stars in a cluster being expected to have formed at roughly the same time.
According to the researchers, the discovery sheds new light on stellar evolution and binary star interactions. The system was found within the so-called “brown dwarf desert” — a region where such companions are considered extremely rare.
The findings, published in the journal Monthly Notices of the Royal Astronomical Society: Letters, also suggest that the system may have formed through the evolution of a triple-star system involving stellar mergers and orbital interactions.
Scientists said the breakthrough could significantly improve theoretical models related to stellar evolution, compact binaries and substellar objects, while also encouraging young researchers to explore astronomical discoveries using archival data.
