1.
A region of spacetime where gravity is so strong that nothing, not even light, can escape.
2.
The boundary around a black hole beyond which no light or information can escape.
3.
The theoretical point of infinite density at the center of a black hole.
4.
The super-dense remnant of a massive star's supernova explosion.
5.
A rapidly rotating neutron star that emits beams of electromagnetic radiation.
6.
A rotating disk of gas and dust orbiting a compact object like a black hole or neutron star.
7.
A neutron star with an extremely powerful magnetic field.
8.
A very luminous active galactic nucleus, believed to be powered by a supermassive black hole
9.
The prevailing cosmological model describing the universe's earliest moments and subsequent evolution.
10.
Hypothetical form of matter that does not interact with light or other electromagnetic radiation, but whose gravitational effects are observable.
11.
A mysterious form of energy thought to be responsible for the accelerating expansion of the universe.
12.
A term in Einstein's field equations of general relativity that represents a constant energy density of empty space, linked to dark energy.
13.
The powerful and luminous explosion of a star.
14.
The dense, hot remnant of a low-to-medium mass star after it has shed its outer layers
15.
A large, luminous star that has exhausted the hydrogen fuel in its core and expanded.
16.
The maximum mass a stable white dwarf star can have.
17.
Einstein's theory of gravitation, which describes gravity as a curvature of spacetime caused by mass and energy.
18.
Ripples in the fabric of spacetime, predicted by Einstein's theory of general relativity and now detected directly.
19.
A change in the observed frequency or wavelength of a wave, such as light, caused by the relative motion of the source and observer.
20.
The theory describing the behavior of matter at the atomic and subatomic level, essential for understanding many astrophysical processes.
