Gravitational Lensing Archives

April 3, 2023April 3, 2023 by Matt Williams

Astronomers Think They've Found One of the Biggest Black Holes Ever Seen

Artist's impression of an ultramassive black hole (UBH). Credit: ESA/Hubble/DSS/Nick Risinger/N. Bartmann

In 1931, Indian-American physicist Subrahmanyan Chandrasekhar proposed a resolution to Einstein’s Theory of General Relativity that postulated the existence of black holes. By 1972, astronomers obtained the first conclusive evidence that these objects existed in our Universe. Observations of quasars and the center of the Milky Way also revealed that most massive galaxies have supermassive black holes (SMBHs) at their cores. Since then, the study of black holes has revealed that these objects vary in size and mass, ranging from micro black holes (MBHs) and intermediate black holes (IMBHs) to SMBHs.

Using astronomical simulations and a technique known as Gravitational Lensing, an international team of astrophysicists detected what could be the largest black hole ever observed. This ultramassive black hole (UMBH) has a mass roughly 30 billion times that of our Sun and is located near the center of the Abell 1201 galaxy cluster, roughly 2.7 billion light-years from Earth. This is the first time a black hole has been found using Gravitational Lensing, and it could enable studies that look farther into space to find black holes and deepen our understanding of their size and scale.

March 24, 2023March 24, 2023 by Evan Gough

A Rogue Earth and Neptune Might Have Been Found in Older Data

An artist's illustration of a rogue planet, dark and mysterious. Image Credit: NASA

Scientists have found what appear to be rogue planets hidden in old survey data. Their results are starting to define the poorly-understood rogue planet population. In the near future, the Nancy Grace Roman Space Telescope will conduct a search for more free-floating planets, and the team of researchers developed some methods that will aid that search.

January 23, 2023January 23, 2023 by Matt Williams

A Novel Propulsion System Would Hurl Hypervelocity Pellets at a Spacecraft to Speed it up

Graphic depiction of Pellet-Beam Propulsion for Breakthrough Space Exploration. Credits: Artur Davoyan

Today, multiple space agencies are investigating cutting-edge propulsion ideas that will allow for rapid transits to other bodies in the Solar System. These include NASA’s Nuclear-Thermal or Nuclear-Electric Propulsion (NTP/NEP) concepts that could enable transit times to Mars in 100 days (or even 45) and a nuclear-powered Chinese spacecraft that could explore Neptune and its largest moon, Triton. While these and other ideas could allow for interplanetary exploration, getting beyond the Solar System presents some major challenges.

As we explored in a previous article, it would take spacecraft using conventional propulsion anywhere from 19,000 to 81,000 years to reach even the nearest star, Proxima Centauri (4.25 light-years from Earth). To this end, engineers have been researching proposals for uncrewed spacecraft that rely on beams of directed energy (lasers) to accelerate light sails to a fraction of the speed of light. A new idea proposed by researchers from UCLA envisions a twist on the beam-sail idea: a pellet-beam concept that could accelerate a 1-ton spacecraft to the edge of the Solar System in less than 20 years.

October 31, 2022October 31, 2022 by Carolyn Collins Petersen

In a New Hubble Image, Dark Matter Anchors the Giant Galaxy Cluster Abell 611

abell 611 and its galaxies and dark matter — Hubble Space Telescope offers a cosmic cobweb of galaxies and invisible dark matter in the cluster Abell 611. Credit: ESA/Hubble, NASA, P. Kelly, M. Postman, J. Richard, S. Allen

Dark matter. It’s secret. It’s dark because it doesn’t give off any light. We can’t see it, taste it, touch it, smell it, or even feel it. But, astronomers can measure this dark secret of the universe. How? By looking at galaxies and galaxy clusters. Dark matter exerts a gravitational influence on those regions, and that CAN be measured.

October 7, 2022October 7, 2022 by Nancy Atkinson

Webb and Hubble Work Together to Reveal This Spectacular Galaxy Pair — and Several Bonuses!

By combining data from the James Webb Space Telescope and the Hubble Space Telescope, this image of galaxy pair VV 191 includes near-infrared light from Webb, and ultraviolet and visible light from Hubble. Credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team, Alyssa Pagan (STScI).

What’s better than a pair of galaxies observed by a pair of iconic space telescopes? The answer to that, according to researchers using the Hubble and James Webb Space Telescopes, is finding even more galaxies and other remarkable details no one expected in the duo’s observations.

“Galaxies in the foreground, background, deep background, and into the depths,” said astronomer William Keel from Galaxy Zoo, on Twitter.

September 30, 2022September 30, 2022 by Nancy Atkinson

A Computer Algorithm is 88% Accurate in Finding Gravitational Lenses

Pictures of gravitational lenses from the AGEL survey. Credit: ARC Centre of Excellence for All Sky Astrophysics in 3-Dimensions (ASTRO3D) and the University of NSW (UNSW).

Astronomers have been assessing a new machine learning algorithm to determine how reliable it is for finding gravitational lenses hidden in images from all sky surveys. This type of AI was used to find about 5,000 potential gravitational lenses, which needed to be confirmed. Using spectroscopy for confirmation, the international team has now determined the technique has a whopping 88% success rate, which means this new tool could be used to find thousands more of these magical quirks of physics.

September 25, 2022September 25, 2022 by Carolyn Collins Petersen

Gravity Really Tangled up the Light From a Distant Quasar

quasar lensed — The SDSS J1004+4112 gravitational lens creates five images of a distant quasar. Credit: European Space Agency, NASA, Keren Sharon (Tel-Aviv University) and Eran Ofek (CalTech))

Way back in 1979, astronomers spotted two nearly identical quasars that seemed close to each other in the sky. These so-called “Twin Quasars” are actually separate images of the same object. Even more intriguing: the light paths that created each image traveled through different parts of the cluster. One path took a little longer than the other. That meant a flicker in one image of the quasar occurred 14 months later in the other. The reason? The cluster’s mass distribution formed a lens that distorted the light and drastically affected the two paths.

July 24, 2022July 24, 2022 by Carolyn Collins Petersen

Hubble Sees a Mirror Image of the Same Galaxy Thanks to Gravitational Lensing

Gravitational lensing and SGAS J143845+145407

It’s been an amazing couple of weeks for fans of gravitational lensing. JWST grabbed the headlines with a spectacular infrared view of lensing in the SMACS 0723 image, and that had everybody talking. Yet, seeing gravitationally lensed objects is not new. Some can be seen from the ground, and of course, Hubble Space Telescope (HST) has been cranking out views of gravitational lensing for years.

Just a few days ago, HST released another one. It’s a striking view of a distant galaxy called SGAS J143845+145407. It’s the centerpiece of the HST view and appears twice in a mirror image of itself. The galaxy appears a third time, as a very smeared apparition that makes a “bridge” between the other two images.

July 23, 2022July 23, 2022 by Andy Tomaswick

A Mission to Reach the Solar Gravitational Lens in 30 Years

NASA’s Institute for Advanced Concepts is famous for supporting outlandish ideas in the astronomy and space exploration fields. Since being re-established in 2011, the institute has supported a wide variety of projects as part of its three-phase program. However, so far, only three projects have gone on to receive Phase III funding. And one of those just released a white paper describing a mission to get a telescope that could effectively see biosignatures on nearby exoplanets by utilizing the gravitational lens of our own Sun.

June 17, 2022June 17, 2022 by Nancy Atkinson

Using the Sun as a Gravitational Lens Would Let Us See Exoplanets With Incredible Resolution

An artist view of countless exoplanets. Credit: NASA/JPL-Caltech

Have you ever seen wispy arcs and rings in astronomical images taken by the Hubble Space Telescope and other observatories? These unusual features are caused by a quirk of nature called gravitational lensing, which occurs when light from a distant object is distorted by a closer massive object along the same line of sight. This distortion effectively creates a giant lens which magnifies the background light source, allowing astronomers to observe objects embedded within those lens-created arcs and rings that are otherwise be too far and too dim to see.

A group of researchers are working on plans to build a spacecraft that could apply this quirk by using our Sun as a gravitational lens. Their goal is to see distant exoplanets orbiting other stars, and to image an Earth-like exoplanet, seeing it in exquisite detail, at a resolution even better than the well-known Apollo 8 Earthrise photo.