Astronomers from ARIES (Nainital) and PRL (Ahmedabad) used the Devasthal Fast Optical Telescope (DFOT) and NASA’s TESS to study W Ursae Majoris stars—a unique type of "contact binary."
Scientific Significance
- What are they? These are binary star systems where two stars are so close that they touch each other, sharing a common outer atmosphere (common envelope).
- The Research: By analyzing "light curves" (how brightness changes over time), scientists found evidence of star spots (magnetic activity) and mass transfer between the twins.
- Why study them? They serve as "natural laboratories" for understanding stellar evolution and the eventual fate of stars (mergers or supernovae).
UPSC - 2027 - Prelims cum Mains - Foundation Course / Orientation on 08-03-2026 
