Event horizons, supernovas, neutron stars, and astrophysics.
Test your knowledge with these top questions!
Which remnant forms if a core-collapse supernova leaves a core below the black-hole threshold?
A core-collapse supernova can leave a neutron star below the black-hole threshold; a more massive remnant can instead become a black hole.
What event marks the explosive death of a massive star?
A supernova can briefly outshine an entire galaxy and forge heavy elements such as gold.
What boundary marks the point of no return around a black hole?
Gravity at the event horizon is so strong that even light cannot escape, giving black holes their inescapable pull.
What do astronomers detect when two black holes merge?
LIGO's 2015 detection of colliding black holes confirmed gravitational waves, which Einstein predicted in 1916.