As of 2010, the closest known black hole to Earth is V4641 Sgr. According to Tega Jessa of Universe Today, V4641 Sgr is located in the Sagittarius arm of the Milky Way galaxy and was first discovered in 1999. This black hole is 1600 light years from Earth.Know More
Black holes are the last stage in a star's life cycle, forming when a star collapses under the weight of its own gravity, explains Jessa. They are discovered using radio telescopes, which detect radioactive emissions from matter that falls into them.
Based on Einstein's theory of general relativity, objects can fall or be pulled into a black hole, but they can never reappear. Because black holes are basically invisible, scientists rely on the observation of matter surrounding the possible location of a black hole.Learn more about Stellar Astronomy
Scientists believe galaxies form in one of two ways: superheated gas collapses upon itself to form huge clumps of stellar material before merging with other clumps to form galaxies, or clumps of superheated gas are the size of dozens of galaxies before breaking apart into smaller units. There are more than 100 billion galaxies of varying sizes, according to How Stuff Works.Full Answer >
The outer layers of the star undergo a supernova explosion, leaving behind a collapsed star called a neutron star. Stars of 1.4 to three times the mass of the sun give birth to neutron stars. In neutron stars, atoms are crushed while protons seize the electrons and transform into neutrons.Full Answer >
Every planet in the solar system and everyone on Earth are located in the Milky Way Galaxy. The Milky Way contains approximately 100 to 400 billion stars, one of which is the sun.Full Answer >
Stargazers know that the stars have celebrated many more birthdays than humans can even imagine, but just how many birthdays is truly astronomical. As of 2015, the oldest known star in the universe is 14.3 billion years old. By comparison, our solar system’s sun is a youthful 4.56 billions years old.Full Answer >