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.
X-ray astronomy helps scientists study neutron stars, binary star systems, and supernova remnants, and even helps detect black holes. But even if human eyes had the ability to see X-rays, we couldn’t just look up at the night sky and see these amazing objects since Earth’s atmosphere absorbs and blocks X-rays. So, thank goodness for space telescopes! And the newest X-ray instrument in space has just produced a breathtaking view of the Universe, and is the deepest X-ray view of the sky we’ve ever seen.
Hundreds of millions of light years away, a supermassive black hole sits in the center of a galaxy cluster named Ophiuchus. Though black holes are renowned for sucking in surrounding material, they sometimes expel material in jets. This black hole is the site of an almost unimaginably powerful explosion, created when an enormous amount of material was expelled.
Astronomers have found a supermassive black hole (SMBH) with an unusually regular feeding schedule. The behemoth is an active galactic nucleus (AGN) at the heart of the Seyfert 2 galaxy GSN 069. The AGN is about 250 million light years from Earth, and contains about 400,000 times the mass of the Sun.
A rogue star is one that has escaped the gravitational pull of its home galaxy. These stars drift through intergalactic space, and so are sometimes called intergalactic stars. Sometimes, when a rogue star is ejected from its galaxy, it drags its binary pair along for the ride.