Gravitational Waves Archives

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.

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).

October 11, 2022October 11, 2022 by Evan Gough

Two Stars Orbiting Each Other Every 51 Minutes. This Can’t End Well

An artist’s illustration shows a white dwarf (right) circling a larger, sun-like star (left) in an ultra-short orbit, forming a “cataclysmic” binary system. Credits:Credit: M.Weiss/Center for Astrophysics | Harvard & Smithsonian

We don’t have to worry too much about our Sun. It can burn our skin, and it can emit potent doses of charged material—called Solar storms—that can damage electrical systems. But the Sun is alone up there, making things simpler and more predictable.

Other stars are locked in relationships with one another as binary pairs. A new study found a binary pair of stars that are so close to each other they orbit every 51 minutes, the shortest orbit ever seen in a binary system. Their proximity to one another spells trouble.

October 7, 2022October 7, 2022 by Evan Gough

Binary Stars Live Complicated Lives, Especially Near the End

Artist's impression of a red giant star. If the star is in a binary pair, what happens to its sibling? Credit:NASA/ Walt Feimer

We know what will happen to our Sun.

It’ll follow the same path other stars of its ilk follow. It’ll start running out of hydrogen, swell up and cool and turn red. It’ll be a red giant, and eventually, it’ll become so voluminous that it will consume the planets closest to it and render Earth uninhabitable. Then billions of years from now, it’ll create one of those beautiful nebulae we see in Hubble images, and the remnant Sun will be a shrunken white dwarf in the center of the nebula, a much smaller vestige of the luminous body it once was.

This is the predictable life the Sun lives as a solitary star. But what happens to stars that have a solar sibling? How would its binary companion fare?

August 24, 2022August 24, 2022 by Brian Koberlein

Colliding Black Holes Provide Another way to Measure Distance in the Universe

A simulation of two merging black holes. Credit: Simulating eXtreme Spacetimes (SXS) Project

We know the universe is expanding, and we have a pretty good idea of how fast it’s expanding, but we don’t know the rate exactly. That’s because of the different methods we have to measure the rate of cosmic expansion keep giving us slightly different results. It’s a nagging problem that bugs astronomers, so while they have worked to ensure current methods are accurate, they have also looked to new ways to measure cosmic expansion. One of these new ways involves gravitational waves.

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.

July 28, 2022July 28, 2022 by Matt Williams

A Black Hole can Tear a Neutron Star Apart in Less Than 2 Seconds

Numerical simulation of a black hole-neutron star merger. Credit and ©: K. Hayashi (Kyoto University)

Almost seven years ago (September 14th, 2015), researchers at the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves (GWs) for the first time. Their results were shared with the world six months later and earned the discovery team the Noble Prize in Physics the following year. Since then, a total of 90 signals have been observed that were created by binary systems of two black holes, two neutron stars, or one of each. This latter scenario presents some very interesting opportunities for astronomers.

If a merger involves a black hole and neutron star, the event will produce GWs and a serious light display! Using data collected from the three black hole-neutron star mergers we’ve detected so far, a team of astrophysicists from Japan and Germany was able to model the complete process of the collision of a black hole with a neutron star, which included everything from the final orbits of the binary to the merger and post-merger phase. Their results could help inform future surveys that are sensitive enough to study mergers and GW events in much greater detail.

April 12, 2022 by Shawn DiCenza

Gamma ray Telescopes Might be Able to Detect the Gravitational Waves Caused by Merging Supermassive Black Holes

Gamma rays could be the new source for observing gravitational waves, according to a recent release from the Max Planck Institute for Radio Astronomy. This would make a possible third way to observe gravitational waves including laser interferometry and radio waves.

In 1916 Einstein predicted the existence of gravitational waves, ripples in space-time moving out in all directions away from massive accelerating objects. According to his theory, these waves would travel at the speed of light and would carry with them information about where they came from and would allow us to learn more about gravity.

Continue reading “Gamma ray Telescopes Might be Able to Detect the Gravitational Waves Caused by Merging Supermassive Black Holes”

March 2, 2022March 2, 2022 by Evan Gough

The Expanding Debris Cloud From the Kilonova Tells the Story of What Happens When Neutron Stars Collide

This artist’s conception illustrates the aftermath of a "kilonova," a powerful event that happens when two neutron stars merge. The object is called GW170817 and is the only cosmic event where both gravitational waves and electromagnetic radiation were detected. Image Credit: X-ray: NASA/CXC/Northwestern Univ./A. Hajela et al.; Illustration: NASA/CXC/M.Weiss

When two neutron stars collide, it creates a kilonova. The event causes both gravitational waves and emissions of electromagnetic energy. In 2017 the LIGO-Virgo gravitational-wave observatories detected a merger of two neutron stars about 130 million light-years away in the galaxy NGC 4993. The merger is called GW170817, and it remains the only cosmic event observed in both gravitational waves and electromagnetic radiation.

Astronomers have watched the expanding debris cloud from the kilonova for years. A clearer picture of what happens in the aftermath is emerging.

February 2, 2022February 2, 2022 by Matt Williams

A Highly Eccentric Black Hole Merger Detected for the First Time

In February 2016, scientists with the Laser Interferometer Gravitational-Wave Observatory (LIGO) confirmed the first-ever detection of a gravitational wave event. Originally predicted by Einstein’s Theory of General Relativity, GWs result from mergers between massive objects – like black holes, neutron stars, and supermassive black holes (SMBHs). Since 2016, dozens of events have been confirmed, opening a new window to the Universe and leading to a revolution in astronomy and cosmology.

In another first, a team of scientists led by the Center for Computational Relativity and Gravitation (CCRG) announced that they may have detected a merger of two black holes with eccentric orbits for the first time. According to the team’s paper, which recently appeared in Nature Astronomy, this potential discovery could explain why some of the black hole mergers detected by the LIGO Scientific Collaboration and the Virgo Collaboration are much heavier than previously expected.