1. Gravitational Waves
These are ripples in spacetime caused by the acceleration of massive objects. They were predicted by Einstein's theory of general relativity and detected for the first time in 2015 by the Laser Interferometer Gravitational-Wave Observatory (LIGO).
2. Pulsars
Pulsars are highly magnetized, rotating neutron stars that emit beams of electromagnetic radiation. They were first discovered in 1967 and are incredibly precise timekeepers, rivaling atomic clocks in accuracy.
3. Cosmic Web
The large-scale structure of the universe resembles a vast cosmic web, with galaxies and galaxy clusters connected by filaments of dark matter and gas, surrounding vast voids.
4. Cosmic Inflation
Inflation is a theory that proposes the universe underwent a rapid exponential expansion in the first moments after the Big Bang. It helps explain the uniformity of the cosmic microwave background radiation and the large-scale structure of the universe.
5. White Dwarfs and Supernovae
White dwarfs are the remnants of low to medium mass stars, like our Sun, after they have exhausted their nuclear fuel. Supernovae occur when massive stars undergo a catastrophic explosion at the end of their life cycle, sometimes leaving behind neutron stars or black holes.
6. Galactic Cannibalism
Larger galaxies can devour smaller ones through a process called galactic cannibalism, where smaller galaxies are torn apart and absorbed into the larger one.
7. Quasars
These are extremely bright and distant objects powered by supermassive black holes at the centers of galaxies. They emit immense amounts of energy, outshining entire galaxies, and are thought to be active in the early universe.
8. Age of the Oldest Star
The oldest known star in the universe, Methuselah, is estimated to be about 14.5 billion years old, just a few hundred million years younger than the universe itself.
9. The Great Attractor
There's a gravitational anomaly in the cosmos called the Great Attractor, which influences the motion of galaxies in our local universe. Its exact nature is still a topic of research and debate.
10. Cosmic Microwave Background Anisotropies
Tiny fluctuations in the cosmic microwave background radiation provide valuable insights into the early universe's density variations, which eventually led to the formation of galaxies and large-scale structures.