Dark matter is a hypothetical type of matter that is invisible and doesn't interact with light or other electromagnetic radiation. It is believed to occupy 27% of the universe, and is responsible for the structure and evolution of galaxies. Their detection is hard as they don’t really interact with ordinary matter or radiation except through gravity.
Also known as free-floating planets (FFP) or isolated planetary-mass objects (iPMO), rogue planets are planets that are not bound to a star and floats freely in space. They get separated from their planetary system due to gravitational interactions.
Pulsars are neutron stars with a strong magnetic field that emits radiation in regular pulses. They are formed when the core of a star collapses inward and becomes compressed in a supernova. They are often known as cosmic lighthouses. Pulsars are very dense, with a teaspoon of pulsar material weighing a billion tonnes on Earth.
A quasar is an intensely luminous astronomical object located at the center of certain galaxies, powered by gas spiraling at high speed into a massive black hole. The brightest quasars can outshine all stars in the galaxy, hence they are visible even at distances of billions of light-years.
A neutron star is the result of a massive star's supernova explosion and gravitational collapse. The core of the star is compressed to the density of atomic nuclei, which is denser than a white dwarf star. Neutron stars are made up of neutrons, protons, and electrons. However the extreme pressure in a neutron star causes the protons and electrons to combine into neutrons.
A magnetar is a type of neutron star that has an extremely powerful magnetic field. The magnetic field of a magnetar is over 1,000 times stronger than that of a pulsar. When a magnetar's magnetic field rearranges itself, it can create starquakes and intense flares. These flares release a burst of radiation that we detect as gamma rays.
The region in space where gravity is so strong that nothing, not even light, can escape is known as Black hole. are created when a massive star dies and its core collapses. The star's outer layers are blown away, and the remaining core is compressed into a tiny point with infinite density, which is known as singularity.