Indian Scientists Discover One of World’s Shortest-Period Stellar Binary Systems
Researchers identify rare blue straggler star with brown dwarf companion orbiting every 5.6 hours, offering new clues into stellar evolution
Artistic impression of the discovered compact binary system showing a BSS primary orbited by a BD companion in an ultra-short, nearly circular orbit with a period of about 5.6 hours
New Delhi: Indian and international astronomers have made a major breakthrough in stellar astrophysics by confirming the discovery of a rare blue straggler star hosting a brown dwarf companion in one of the shortest-period compact binary systems ever observed.
The discovery, announced by the ministry of science and technology on Tuesday, is expected to deepen scientific understanding of stellar evolution, binary star interactions and the mysterious class of stars known as blue stragglers.
The research was carried out by scientists from Gauhati University, Indian Institute of Astrophysics, Aryabhatta Research Institute of Observational Sciences and INAF-Catania Astrophysical Observatory under the INSPIRE programme of the Department of Science and Technology (DST).
Blue straggler stars have long puzzled astronomers because they appear hotter, 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.
The team discovered that the newly identified binary system has an exceptionally short orbital period of around 5.6 hours, or 0.234 days. The companion object has a mass of only about 0.056 times that of the Sun, placing it below the hydrogen-burning threshold and classifying it as a brown dwarf — an object too massive to be a planet but too small to become a true star.
Scientists said this is the lightest companion ever detected around a blue straggler star and represents the shortest-period binary system discovered within the so-called “brown dwarf desert,” a region where such companions are considered extremely rare.
The research team included Ali Hasan Sheikh, Biman J. Medhi, Sergio Messina, Annapurni Subramanium, Ram Sagar and Neelam Panwar.
According to the researchers, the rapidly rotating blue straggler and its substellar companion provide important clues about how stars exchange mass, survive close interactions and evolve in extreme environments.
The findings are expected to help refine theoretical models used in studying stellar evolution, binary systems and substellar objects, improving the interpretation of data from major ground-based observatories and space missions.
The study has been published in the journal Monthly Notices of the Royal Astronomical Society: Letters.
Publication details are available at Oxford Academic DOI Page.
