black holes tagged posts

A team of astronomers has claimed that observations of a sun-like star orbiting a small black hole might actually be the indication of something far more exotic—the existence of a boson star, a star composed entirely of dark matter.

The Gaia survey, led by the European Space Agency, provided detailed maps of more than a billion stars in the Milky Way galaxy. While almost all of those stars behaved as expected, there were some surprises. For example, one star in particular was seen orbiting a dark companion.

The star itself was fairly typical, weighing in at 0.93 solar masses and with roughly the same chemical abundance as our own sun...

Observations of supermassive black holes at the centers of galaxies point to a likely source of dark energy—the ‘missing’ 70% of the universe.

The measurements from ancient and dormant galaxies show black holes growing more than expected, aligning with a phenomenon predicted in Einstein’s theory of gravity. The result potentially means nothing new has to be added to our picture of the universe to account for dark energy: black holes combined with Einstein’s gravity are the source.

The conclusion was reached by a team of 17 researchers in nine countries, led by the University of Hawai’i a...

Black holes form natural time machines that allow travel to both the past and the future. But don’t expect to be heading back to visit the dinosaurs any time soon.

At present, we don’t have spacecraft that could get us anywhere near a black hole. But, even leaving that small detail aside, attempting to travel into the past using a black hole might be the last thing you ever do.

What are black holes?

A black hole is an extremely massive object that is typically formed when a dying star collapses in on itself.

Like planets and stars, black holes have gravitational fields around them. A gravitational field is what keeps us stuck to Earth, and what keeps Earth revolving around the Sun.

As a rule of thumb, the mor...

Study adds more certainty to theory involving information paradox. Black holes really are giant fuzzballs, a new study says.

The study attempts to put to rest the debate over Stephen Hawking’s famous information paradox, the problem created by Hawking’s conclusion that any data that enters a black hole can never leave. This conclusion accorded with the laws of thermodynamics, but opposed the fundamental laws of quantum mechanics.

“What we found from string theory is that all the mass of a black hole is not getting sucked in to the center,” said Samir Mathur, lead author of the study and professor of physics at The Ohio State University...