Indian researchers spot one of the shortest-period stellar binary system

📌 Summary:

• Indian researchers have made the world's first confirmed discovery of a blue straggler star hosting a brown dwarf companion in an extraordinarily compact binary system.

• The system has an exceptionally short orbital period of about 5.6 hours (0.234 days), among the shortest known, and the companion (about 0.056 times the mass of the Sun) is the lightest ever detected around a blue straggler, placing it below the hydrogen-burning limit.

• It is the shortest-period binary found inside the brown dwarf desert, a region where such companions are believed to be extremely rare.

• The team was drawn from Gauhati University (supported under DST's INSPIRE programme), the Indian Institute of Astrophysics (IIA) Bengaluru, ARIES Nainital, and the INAF-Catania Astrophysical Observatory, Italy.

• The proposed formation pathway is hierarchical triple-star evolution involving mass transfer, Kozai-Lidov oscillations, merger of the progenitor with a tertiary star, and tidal circularisation of the orbit.

• Published in Monthly Notices of the Royal Astronomical Society: Letters, the finding refines models of stellar evolution and shows how analysing archival data can yield major discoveries without expensive new facilities.

🎯 UPSC Relevance: GS3 — Science and Technology; Indian achievements in astrophysics and the role of DST institutions and the INSPIRE programme.

📝 Prelims Facts:

• Blue straggler stars appear brighter and bluer than the main-sequence turn-off in star clusters.

• A brown dwarf is too massive to be a planet but too small to ignite hydrogen fusion as a true star.

• ARIES (Aryabhatta Research Institute of Observational Sciences), Nainital and IIA, Bengaluru are autonomous institutes of the Department of Science and Technology (DST).

• INSPIRE is a DST programme to attract talented students to science.

🔑 Key Term: Brown dwarf — a substellar object more massive than a planet but below the minimum mass needed to sustain hydrogen fusion, known as the hydrogen-burning limit.