Roche Lobe Overflow

Roche Lobe Overflow occurs in a close binary star system when one star expands and fills its gravitational boundary, known as the Roche lobe. Once filled, material from that star can flow directly onto its companion star through the point where their gravitational fields meet, called the L1 point. This transfer of matter can significantly influence the stars' evolution, potentially creating phenomena like X-ray binaries or novae. Essentially, Roche Lobe Overflow is a process where material moves from one star to another due to their gravitational interaction when one star's outer layers extend beyond its gravitational limits.