Gravitational Waves Archives

April 27, 2023April 27, 2023 by Brian Koberlein

Gravitational Waves From Pulsars Could Be Used to Probe the Interior of the Sun

A solar flare, as it appears in extreme ultra-violet light. Some stars emit superflares similar to this, but many times brighter and stronger than those from the Sun. Credit: NASA/SFC/SDO

Gravitational wave astronomy is still in its early stages. So far it has focused on the most energetic and distinct sources of gravitational waves, such as the cataclysmic mergers of black holes and neutron stars. But that will change as our gravitational telescopes improve, and it will allow astronomers to explore the universe in ways previously impossible.

April 7, 2023April 7, 2023 by Paul M. Sutter

Physicists Discover that Gravity Can Create Light

A star is being consumed by a distant supermassive black hole. Astronomers call this a tidal disruption event (TDE). As the black hole rips apart the star, two jets of material moving with almost the speed of light are launched in opposite directions. One of the jets was aimed directly at Earth. Image credit: Carl Knox (OzGrav, ARC Centre of Excellence for Gravitational Wave Discovery, Swinburne University of Technology)

Researchers have discovered that in the exotic conditions of the early universe, waves of gravity may have shaken space-time so hard that they spontaneously created radiation.

March 30, 2023April 2, 2023 by Matt Williams

Gravitational Waves From Colliding Neutron Stars Matched to a Fast Radio Burst

Artist’s impression of a fast radio burst traveling through space and reaching Earth. Credit: ESO/M. Kornmesser

Fast Radio Bursts (FRBs) were first detected in 2007 (the Lorimer Burst) and have remained one of the most mysterious astronomical phenomena ever since. These bright radio pulses generally last a few milliseconds and are never heard from again (except in the rare case of Repeating FRBs). And then you have Gravitational Waves (GW), a phenomenon predicted by General Relativity that was first detected on September 14th, 2015. Together, these two phenomena have led to a revolution in astronomy where events are detected regularly and provide fresh insight into other cosmic mysteries.

In a new study led by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav), an Australian-American team of researchers has revealed that FRBs and GWs may be connected. According to their study, which recently appeared in the journal Nature Astronomy, the team noted a potential coincidence between a binary neutron star merger and a bright non-repeating FRB. If confirmed, their results could confirm what astronomers have expected for some time – that FRBs are caused by a variety of astronomical events.

January 31, 2023January 31, 2023 by Carolyn Collins Petersen

Soon We’ll Detect Extreme Objects Producing Gravitational Waves Continuously

An artist's concept of a binary pair where a smaller star is feeding material to a neutron star. Perturbations in the neutron star may be sending a constant wash of gravitational waves through space. Courtesy Gabriel Pérez Díaz, SMM (IAC)

The cosmic zoo contains objects so bizarre and extreme that they generate gravitational waves. Scorpius X-1 is part of that strange collection. It’s actually a binary pair: a neutron star orbiting with a low-mass stellar companion called V818 Scorpii. The pair provides a prime target for scientists hunting for so-called “continuous” gravitational waves. Those waves should exist, although none have been detected—yet.

December 19, 2022December 19, 2022 by Matt Williams

Gravitational Wave Observatories Could Search for Warp Drive Signatures

Artist's impression of a Dyson Sphere. The construction of such a massive engineering structure would create a technosignature that could be detected by humanity. Credit: SentientDevelopments.com/Eburacum45

In 2016, scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced that they had made the first confirmed detection of gravitational waves (GWs). This discovery confirmed a prediction made a century before by Einstein and his Theory of General Relativity and opened the door to a whole new field of astrophysical research. By studying the waves caused by the merger of massive objects, scientists could probe the interior of neutron stars, detect dark matter, and discover new particles around supermassive black holes (SMBHs).

According to new research led by the Advanced Propulsion Laboratory at Applied Physics (APL-AP), GWs could also be used in the Search for Extraterrestrial Intelligence (SETI). As they state in their paper, LIGO and other observatories (like Virgo and KAGRA) have the potential to look for GWs created by Rapid And/or Massive Accelerating spacecraft (RAMAcraft). By combining the power of these and next-generation observatories, we could create a RAMAcraft Detection And Ranging (RAMADAR) system that could probe all the stars in the Milky Way (100 to 200 billion) for signs of warp-drive-like signatures.

December 12, 2022December 12, 2022 by Carolyn Collins Petersen

Black Holes Shouldn’t be Able to Merge, but Dozens of Mergers Have Been Detected. How Do They Do It?

black holes in a globular cluster — This is an artist’s impression created to visualize the concentration of black holes at the center of globular cluster NGC 6397. Credit: ESA/Hubble, N. Bartmann

Who knows what lurks in the hearts of some globular clusters? Astronomers using a collection of gravitational wave observatories found evidence of collections of smaller black holes dancing together as binaries in the hearts of globulars. What’s more, they’ve detected an increased number of gravitational wave events when some of these stellar-mass black holes crashed together.

October 18, 2022October 18, 2022 by Matt Williams

Hubble Examines the Wreckage From the 2017 Kilonova

Artist's impression of two neutron stars colliding, known as a "kilonova" event. Credits: Elizabeth Wheatley (STScI)

In August 2017, astronomers observed a Gravitational Wave (GW) signal that resulted from the merger of two neutron stars – known as a “kilonova” event. The aftermath of this event (GW170817) was studied by 70 ground-based and space-based observatories in multiple wavelengths. This was the first time astronomers observed a binary neutron star merger in terms of electromagnetic radiation (particularly gamma rays) and GWs. The energy released by this merger was comparable to that of a supernova, leading astronomers to theorize that it must have resulted in a black hole.

Two years later, the Hubble Space Telescope observed the remnant and noted the powerful afterglow and gamma-ray bursts (GRBs) created by the merger, which was consistent with a black hole. However, it would take several more years of analysis before scientists could draw a complete picture of what resulted from this explosive event. Using data from Hubble and several radio observatories, a team of researchers detected a rapidly-rotating disk of material around the black hole and a structured relativistic jet emanating from it.

October 17, 2022December 7, 2022 by Matt Williams

Shortly Before They Collided, two Black Holes Tangled Spacetime up Into Knots

A binary black hole system, viewed from above. Image Credit: Bohn et al. (see http://arxiv.org/abs/1410.7775)

In February 2016, scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced the first-ever detection of gravitational waves (GWs). Originally predicted by Einstein’s Theory of General Relativity, these waves are ripples in spacetime that occur whenever massive objects (like black holes and neutron stars) merge. Since then, countless GW events have been detected by observatories across the globe – to the point where they have become an almost daily occurrence. This has allowed astronomers to gain insight into some of the most extreme objects in the Universe.

In a recent study, an international team of researchers led by Cardiff University observed a binary black hole system originally detected in 2020 by the Advanced LIGO, Virgo, and Kamioki Gravitational Wave Observatory (KAGRA). In the process, the team noticed a peculiar twisting motion (aka. a precession) in the orbits of the two colliding black holes that was 10 billion times faster than what was noted with other precessing objects. This is the first time a precession has been observed with binary black holes, which confirms yet another phenomenon predicted by General Relativity (GR).

August 22, 2022August 22, 2022 by Brian Koberlein

Gravitational Waves Will Give Astronomers a new way to Look Inside Neutron Stars

Illustration showing the merger of two neutron stars. Credit: NASA's Goddard Space Flight Center/CI Lab

It’s difficult to study neutron stars. They are light years away and only about 20 kilometers across. They are also made of the most dense material in the universe. So dense that atomic nuclei merge together to become a complex fluid. For years our understanding of the interiors was based on complex physical models and what little data we could gather from optical telescopes. But that’s starting to change.

August 9, 2022August 13, 2022 by Paul M. Sutter

Gravitational Waves Near a Neutron Star Could Generate Photons

Artist view of colliding neutron stars. Credit: ESO/L. Calçada/M. Kornmesser

In addition to their intense magnetic fields and copious output of x-ray radiation, neutron stars might have one more trick up their sleeves. They might be able to turn gravitational waves into an extra source of photons.