Black holes swallow everything—including light—which explains why we can’t see them. But we can observe their immediate surroundings and learn about them. And when they’re on a feeding binge, their surroundings become even more luminous and observable.
This increased luminosity allowed astronomers to find a black hole that was feasting on material only 800 million years after the Universe began.
Black holes are confounding objects that stretch physics to its limits. The most massive ones lurk in the centers of large galaxies like ours. They dominate the galactic center, and when a star gets too close, the black hole’s powerful gravitational force tears the star apart as they feed on it. Not even the most massive stars can resist.
But supermassive black holes (SMBHs) didn’t start out that massive. They attained their gargantuan mass by accreting material over vast spans of time and by merging with other black holes.
There are large voids in our understanding of how SMBHs grow and evolve, and one way astrophysicists fill those voids is by watching black holes as they consume stars.
From a distance, supernovae explosions are fascinating. A star more massive than our Sun runs out of hydrogen and becomes unstable. Eventually, it explodes and releases so much energy it can outshine its host galaxy for months.
But space is vast and largely empty, and supernovae are relatively rare. And most planets don’t support life, so most supernovae probably explode without affecting living things.
But a new study shows how one type of supernova has a more extended reach than thought. And it could have consequences for planets like ours.
Black holes. They used to be theoretical, up until the first one was found and confirmed back in the late 20th Century. Now, astronomers find them all over the place. We even have direct radio images of two black holes: one in M87 and Sagittarius A* in the center of our galaxy. So, what do we know about them? A lot. But, there’s more to find out. A team of astronomers using Chandra X-ray Observatory data has made a startling discovery about a central supermassive black hole in a quasar embedded in a distant galaxy cluster. What they found provides clues to the origin and evolution of supermassive black holes.
On July 7, 2020, the X-ray instrument eROSITA captured an astronomical event that – until then – had only been theorized and never seen. It saw the detonation of a nova on a white dwarf star, which produced a so-called fireball explosion of X-rays.
“It was to some extent a fortunate coincidence, really,” said Ole König from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), who led the team of scientists who have published a new paper on the discovery. “These X-ray flashes last only a few hours and are almost impossible to predict, but the observational instrument must be pointed directly at the explosion at exactly the right time.”
Why is there so much antimatter in the Universe? Ordinary matter is far more plentiful than antimatter, but scientists keep detecting more and more antimatter in the form of positrons. More positrons reach Earth than standard models predict. Where do they come from?
Scientists think pulsars are one source, and a new study strengthens that idea.
It’s first light for one of the newest space observatories! The Imaging X-Ray Polarimetry Explorer team has released their first image, taken after a month-long commissioning phase for the spacecraft. And it’s a beauty.
IXPE looked at a favorite target among space observatories, the supernova remnant Cassiopeia A. While x-rays are invisible to human eyes, the amount of magenta color in this image corresponds to the intensity of X-ray light observed. Needless to say, it’s intense with high energy x-rays.
A new mission has launched to study some the most intriguing secrets of the universe. No, not THAT spacecraft (JWST is scheduled for launch on December 22). Another new and exciting mission is called Imaging X-ray Polarimetry Explorer (IXPE) and it will allow scientists to explore the hidden details of some of the most extreme and high-energy objects in the cosmos, such as black holes, neutron stars, pulsars and dozens of other objects.
In 1916, Albert Einstein put the finishing touches on his Theory of General Relativity, a journey that began in 1905 with his attempts to reconcile Newton’s own theories of gravitation with the laws of electromagnetism. Once complete, Einstein’s theory provided a unified description of gravity as a geometric property of the cosmos, where massive objects alter the curvature of spacetime, affecting everything around them.
What’s more, Einstein’s field equations predicted the existence of black holes, objects so massive that even light cannot escape their surfaces. GR also predicts that black holes will bend light in their vicinity, an effect that can be used by astronomers to observe more distant objects. Relying on this technique, an international team of scientists made an unprecedented feat by observing light caused by an X-ray flare that took place behind a black hole.
The core of the Milky Way Galaxy (aka. Galactic Center), the region around which the rest of the galaxy revolves, is a strange and mysterious place. It is here that the Supermassive Black Hole (SMBH) that powers the compact radio source known as Sagittarius A* is located. It is also the most compact region in the galaxy, with an estimated 10 million stars within 3.26 light-years of the Galactic Center.