the.com/binary evolution
two stars locked in orbit, slowly cannibalizing each other until something explodes or gets eaten.
means the study of how two gravitationally bound stars change over time by exchanging mass, merging, or destroying one another as they age.
from emerged mid-20th century once astronomers realized most stars aren't lone wolves — over half live in pairs, and their gravity constantly meddles with each other's life cycles.
mass transferone star literally steals gas from its companion.
algol paradoxlighter star evolved faster, seemingly breaking stellar physics.
common envelopeboth stars can share one shared gaseous atmosphere.
end statesoften ends in supernovae, mergers, or black holes.
for instance
algol system — solved a 1940s puzzle about mismatched stellar aging.
sirius a and b — a white dwarf now orbits its brighter, younger-looking partner.
v445 puppis — a 2000 nova caused by one star feeding on the other.
cygnus x-1 — mass transfer feeding a black hole, discovered in 1964.