Black Holes, Dark Matter

One of the most interesting space studies, after the 2015-detection of gravitational waves from collisions with a black hole, was titled "Limits on Stellar-Mass Compact Objects as Dark Matter from Gravitational Lensing of Type Ia Supernovae," and it was

A team of researchers from the University of Zaragoza, King's College London and the Institute of Astronomy in the UK, led by Ciaran O'Hare, found a collection of stars that were all moving in the same direction. They called this the S1 stream, and these stars are believed to be the remnants of a dwarf galaxy that was swallowed by the Milky Way, billions of years ago.

Over the years, numerous theories from the world of physics and astrophysics have informed the popular perception that black holes function to engulf the luckless particles that venture too close to them, out in space.

What happens to a star when it gets sucked into a black hole? No one knew for sure until Einstein said that he did! The physicist's Theory of Relativity could be used to encompass the physics of such an event. To be more specific, such an occurrence would involve a star passing through the gravitational field of a black hole.

The binary asteroids orbiting each other made their closest approach to Earth on June 21, 2018. The binary nature of the asteroid was confirmed by radar observations, by NASA’s Goldstone Solar system radar, Arecibo Observatory, and Green Bank Observatory. 2017 YE5 is already on its way to get farther from Earth involving in the asteroid belt. It will pass Mars on July 30, 2018. The Earth will witness 2017 YE5 again in 2037, but with a larger distance of 0.2 AU (astronomical unit).

The term 'dark matter' may sound mysterious and sinister. However, it has a role to play in keeping galaxies like ours together, and also, other types of galaxies elsewhere in the universe.

Einstein’s general theory of relatively first introduced the concept of gravitational waves in 1916. Gravitational waves are ‘ripples’ sent out across the universe as a result of massive objects such as black holes merging together and thus causing an alteration in the curvature in spacetime.

Although the galaxy of Cygnus A might be around 800 million light years away, it provides one of the strongest sources of radio waves in our universe. The Very Large Array (VLA) radio telescope located in New Mexico has previously been used to observe Cygnus A since the telescope was built in the 1980s. Cygnus A was observed again by the same telescope in 1996 but after that it wasn’t observed again until 2015 after the telescope had been given an upgrade.

The Fermi bubbles were discovered as recently as 2010, and are comprised of two gamma-ray emitting bubbles expanding 25,000 light-years north and south of the black hole located at the centre of our galaxy, the Milky Way. Whilst the nature and origin of the bubbles was poorly understood at first, astronomers now believe they are due to the release of gases the last time this black hole consumed a large amount of gas.

Supermassive black holes are located in the centre of large galaxies. These black holes are millions of times larger than our own sun, and sustain their existence by ‘feeding’ off the gases around them. This activity can be observed using space telescopes, and is characterized as bright emissions, including x-rays, emanating from the innermost part of the disc surrounding the black hole.