Astronomers catch a star slowly snacking on a brown dwarf, 300 light years away

Key Points:

• Scientists have discovered a unique stellar system, ZTF J0440+2325, about 300 light-years away, where a low-mass star is slowly accreting material from a closely orbiting brown dwarf, marking the first observation of such steady "stellar cannibalism" between two low-mass objects.
• Unlike typical scenarios where stars rapidly engulf planets or brown dwarfs, this system features a slow, steady transfer of material at a rate of about 1/100,000 of Earth's mass per year, potentially continuing for billions of years.
• The discovery was prompted by an unusual triangular light curve detected by the Zwicky Transient Facility, which was initially puzzling but later explained by the steady accretion hotspot rotating into and out of view as the brown dwarf orbits the star every 87 minutes.
• This finding challenges previous assumptions about star-planet interactions and opens new avenues for understanding how low-mass stars and brown dwarfs can coexist and interact over extended timescales without immediate destruction.
• The research team plans to search for more such slow-feeding systems, which could reveal new insights into the dynamics of planetary and substellar companions around stars.