X-Ray Astronomy Archives

April 18, 2023April 18, 2023 by Matt Williams

The Crab Nebula Looks Completely Different in X-Rays, Revealing its Magnetic Fields

Credits: Magnetic field lines: NASA/Bucciantini et al; X-ray: NASA/CXC/SAO; Optical: NASA/STScI; Infrared: NASA-JPL-Caltech

Located about 6,500 light-years away in the constellation Taurus resides one of the best-studied cosmological objects known as the Crab Nebula (aka. Messier 1). Originally discovered in the 18th century by English astronomer John Bevis in 1731, the Crab Nebula became the first object included by astronomer Charles Messier in his catalog of Deep Sky Objects. Because of its extreme nature, scientists have been studying the Crab Nebula for decades to learn more about its magnetic field, its high-energy emissions (x-rays), and how these accelerate particles to close to the speed of light.

Astronomers have been particularly interested in studying the polarization of the x-rays produced by the pulsar and what that can tell us about the nebula’s magnetic field. When studies were first conducted in the 1970s, astronomers had to rely on a sounding rocket to get above Earth’s atmosphere and measure the polarization using special sensors. Recently, an international team of astronomers used data obtained by NASA’s Imaging X-ray Polarimetry Explorer (IXPE) to create a detailed map of the Crab Nebula’s magnetic field that has resolved many long-standing mysteries about the object.

February 3, 2023February 3, 2023 by Evan Gough

Hungry Black Hole was Already Feasting 800 Million Years After the Big Bang

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

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.

December 22, 2022December 22, 2022 by Evan Gough

A Star Came too Close to a Black Hole. It Didn’t End Well

A disk of hot gas swirls around a black hole in this illustration. The stream of gas stretching to the right is what remains of a star that was pulled apart by the black hole. A cloud of hot plasma (gas atoms with their electrons stripped away) above the black hole is known as a corona. Credits: NASA/JPL-Caltech

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.

October 26, 2022October 26, 2022 by Evan Gough

How Dangerous are Nearby Supernovae to Life on Earth?

A composite image of SN 1987A from Hubble, Chandra, and ALMA. Image Credit: By ALMA (ESO/NAOJ/NRAO)/A. Angelich. Visible light image: the NASA/ESA Hubble Space Telescope. X-Ray image: The NASA Chandra X-Ray Observatory - http://www.eso.org/public/images/eso1401a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=30512379

Life and supernovae don’t mix.

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.

June 30, 2022July 11, 2022 by Carolyn Collins Petersen

Most Black Holes Spin Rapidly. This one… Doesn’t

This is the first image of Sgr A*, the supermassive black hole at the centre of our galaxy. Credit: EHT

A Chandra X-ray Observatory view of the supermassive black hole at the heart of quasar H1821+643. Courtesy NASA/CXC/Univ. of Cambridge/J. Sisk-Reynés et al.

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.

May 12, 2022May 12, 2022 by Nancy Atkinson

Astronomers Finally Catch a Nova Detonating on a White Dwarf as it's Happening

Artist impression of an exploding White Dwarf. Credit: University of Tubigen.

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.”

March 17, 2022March 17, 2022 by Evan Gough

A Pulsar is Blasting out Jets of Matter and Antimatter

This image from NASA's Chandra X-ray Observatory and ground-based optical telescopes shows an extremely long beam, or filament, of matter and antimatter extending from a relatively tiny pulsar, as reported in our latest press release. With its tremendous scale, this beam may help explain the surprisingly large numbers of positrons, the antimatter counterparts to electrons, scientists have detected throughout the Milky Way galaxy. Image Credit: X-ray: NASA/CXC/Stanford Univ./M. de Vries; Optical: NSF/AURA/Gemini Consortium

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.

February 16, 2022February 16, 2022 by Nancy Atkinson

The First Image From NASA’s new X-ray Observatory

This image of the supernova remnant Cassiopeia A combines some of the first X-ray data collected by NASA’s Imaging X-ray Polarimetry Explorer, shown in magenta, with high-energy X-ray data from NASA’s Chandra X-Ray Observatory, in blue. Credits: NASA/CXC/SAO/IXPE

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.

December 10, 2021December 10, 2021 by Nancy Atkinson

NASA Launches a New X-ray Observatory

A SpaceX Falcon 9 rocket launches with NASA’s Imaging X-ray Polarimetry Explorer (IXPE) spacecraft onboard from Launch Complex 39A, Thursday, Dec. 9, 2021, at NASA’s Kennedy Space Center in Florida. The IXPE spacecraft is the first satellite dedicated to measuring the polarization of X-rays from a variety of cosmic sources, such as black holes and neutron stars. Launch occurred at 1 a.m. EST. Credits: NASA/Joel Kowsky

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.

August 1, 2021August 1, 2021 by Matt Williams

A Black Hole Emitted a Flare Away From us, but its Intense Gravity Redirected the Blast Back in our Direction

Artist's impression of a black hole, as indicated by its bright accretion disk. Credit: NASA

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.