Gravitational Lensing Archives

April 12, 2024April 24, 2024 by Matt Williams

Formation-Flying Spacecraft Could Probe the Solar System for New Physics

A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO

It’s an exciting time for the fields of astronomy, astrophysics, and cosmology. Thanks to cutting-edge observatories, instruments, and new techniques, scientists are getting closer to experimentally verifying theories that remain largely untested. These theories address some of the most pressing questions scientists have about the Universe and the physical laws governing it – like the nature of gravity, Dark Matter, and Dark Energy. For decades, scientists have postulated that either there is additional physics at work or that our predominant cosmological model needs to be revised.

While the investigation into the existence and nature of Dark Matter and Dark Energy is ongoing, there are also attempts to resolve these mysteries with the possible existence of new physics. In a recent paper, a team of NASA researchers proposed how spacecraft could search for evidence of additional physical within our Solar Systems. This search, they argue, would be assisted by the spacecraft flying in a tetrahedral formation and using interferometers. Such a mission could help resolve a cosmological mystery that has eluded scientists for over half a century.

February 8, 2024February 8, 2024 by Mark Thompson

Gravitationally Lensed Supernovae are Another Way to Measure the Expansion of the Universe

Hubble Space Telescope image of a gravitational lens. — This Hubble Space Telescope image shows the powerful gravity of a galaxy embedded in a massive cluster of galaxies producing multiple images of a single distant supernova far behind it.

Supernova are a fascinating phenomenon and have taught us much about the evolution of stars. The upcoming Nancy Grace Roman telescope will be hunting the elusive combination of supernovae in a gravitational lens system. With its observing field 200 times that of Hubble it stands a much greater chance of success. If sufficient lensed supernovae are found then they could be used to determine the expansion rate of the Universe.

January 10, 2024January 10, 2024 by Carolyn Collins Petersen

Another Example of a Fantastic Einstein Ring

The gravitationally lensed galaxy HerS J020941.1+001557 (red ring) has its imaged distorted by the gravitational effect of a foreground galaxy. Credit: ESA/Hubble & NASA, H. Nayyeri, L. Marchetti, J. Lowenthal; CC BY 4.0 — The gravitationally lensed galaxy HerS J020941.1+001557 (red Einstein ring) has its imaged distorted by the gravitational effect of a foreground galaxy. Credit: ESA/Hubble & NASA, H. Nayyeri, L. Marchetti, J. Lowenthal; CC BY 4.0

The most evocative astronomy images take us across space and time to stars and galaxies billions of light-years away. Nestled at the center of this one, taken by the Hubble Space Telescope, is a collection of three galaxies. They’re not all that close together, although they appear to be in this image. What’s fascinating about this image is that it’s a fine example of an Einstein gravitational ring—and its discovery was enabled by members of the public!

November 11, 2023November 11, 2023 by Matt Williams

An Epic Collaboration Between Hubble and JWST

This panchromatic view of galaxy cluster MACS0416 was created by combining infrared observations from the NASA/ESA/CSA James Webb Space Telescope with visible-light data from the NASA/ESA Hubble Space Telescope. Credit: NASA/ESA/CSA/STScI

In 2012, as part of the MAssive Cluster Survey (MACS), the Hubble Space Telescope (HST) discovered a pair of colliding galaxy clusters (MACS0416) that will eventually combine to form an even bigger cluster. Located about 4.3 billion light-years from Earth, the MACS0416 cluster contains multiple gravitational lenses that allow astronomers to look back in time and view galaxies as they appeared when the Universe was young. In a new collaboration that symbolizes the passing of the torch, the venerable Hubble and the James Webb Space Telescope (JWST) teamed up to conduct an extremely detailed study of MACS0416.

November 4, 2023November 13, 2023 by Matt Williams

Civilizations Could Use Gravitational Lenses to Transmit Power From Star to Star

A new study shows how Solar Gravitational Lenses (SGLs) could be used to beam power from one system to another.. Credit: NASA/ESA

In 1916, famed theoretical physicist Albert Einstein put the finishing touches on his Theory of General Relativity, a geometric theory for how gravity alters the curvature of spacetime. The revolutionary theory remains foundational to our models of how the Universe formed and evolved. One of the many things GR predicted was what is known as gravitational lenses, where objects with massive gravitational fields will distort and magnify light coming from more distant objects. Astronomers have used lenses to conduct deep-field observations and see farther into space.

In recent years, scientists like Claudio Maccone and Slava Turyshev have explored how using our Sun as a Solar Gravity Lens (SGL) could have tremendous applications for astronomy and the Search for Extratterstiral Intelligence (SETI). Two notable examples include studying exoplanets in extreme detail or creating an interstellar communication network (a “galactic internet”). In a recent paper, Turyshev proposes how advanced civilizations could use stellar gravitational lenses to transmit power from star to star – a possibility that could have significant implications in our search for technosignatures.

October 31, 2023October 31, 2023 by Mark Thompson

Can There Be Double Gravitational Lenses?

The narrow galaxy elegantly curving around its spherical companion in this image is a fantastic example of a truly strange and very rare phenomenon. This image, taken with the NASA/ESA Hubble Space Telescope, depicts GAL-CLUS-022058s, located in the southern hemisphere constellation of Fornax (The Furnace). GAL-CLUS-022058s is the largest and one of the most complete Einstein rings ever discovered in our Universe. The object has been nicknamed by the Principal Investigator and his team who are studying this Einstein ring as the "Molten Ring", which alludes to its appearance and host constellation. First theorised to exist by Einstein in his general theory of relativity, this object’s unusual shape can be explained by a process called gravitational lensing, which causes light shining from far away to be bent and pulled by the gravity of an object between its source and the observer. In this case, the light from the background galaxy has been distorted into the curve we see by the gravity of the galaxy cluster sitting in front of it. The near exact alignment of the background galaxy with the central elliptical galaxy of the cluster, seen in the middle of this image, has warped and magnified the image of the background galaxy around itself into an almost perfect ring. The gravity from other galaxies in the cluster is soon to cause additional distortions. Objects like these are the ideal laboratory in which to research galaxies too faint and distant to otherwise see. — Gravitational Lens GAL-CLUS-022058s taken with NASA/ESA Hubble Space Telescope

If you, like me, have used telescopes to gaze out at the wonders of the Universe, then you too may have been a little captivated by the topic of gravitational lensing. Think about it: how cool is it that the very universe we are trying to explore is actually providing us with telescopes to probe the darkest corners of space and time?

The alignment of large clusters of galaxies is the usual culprit whose gravity bends distant light to give us nature’s own telescopes, but now part-time theoretical physicist Viktor T Toth poses the question, “Can there be multiple gravitational lenses lined up and can they provide a ‘communication bridge’ to allow civilisations to communicate?”

October 25, 2023October 25, 2023 by Brian Koberlein

This Photonic Crystal Bends Light Like a Black Hole

Regular and distorted photonic crystals. Credit: K. Kitamura et.al

One of the first observational tests of general relativity was that the path of light bends in the presence of mass. Not only refracts the way light changes direction as it enters glass or other transparent materials, but bends along a curved bath. This effect is central to a range of physical phenomena, from black holes to gravitational lensing to observations of dark matter. But because the effect is so tiny on human scales, we can’t study it easily in the lab. That could change in the future thanks to a new discovery using distorted photonic crystals.

July 27, 2023July 27, 2023 by Carolyn Collins Petersen

Astronomers Find a Rare “Einstein Cross”

A great example of an Einstein Cross, as seen by Hubble Space Telescope. A "galaxy" with five nuclei is really one galaxy surrounded by a mirage of four images of a distant quasar. The galaxy lies 400 million light years away; the quasar about 8 billion. Credit: NASA/ESA/Hubble

Gravitational lensing is one of astronomy’s great wonders: a natural lens that magnifies the distant universe. Sometimes a lensing system takes the shape of a so-called “Einstein Cross”. Those are rare and amazingly useful ways to study objects far away in space and time.

June 18, 2023June 18, 2023 by Matt Williams

Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens

A gravitational lens caused by a galaxy in the foreground leading to an "Einstein Cross." Credit: NASA/ESA/STScI

Measuring cosmic distances is challenging, and astronomers rely on multiple methods and tools to do it – collectively referred to as the Cosmic Distance Ladder. One particularly crucial tool is Type Ia supernovae, which occur in binary systems where one star (a white dwarf) consumes matter from a companion (often a red giant) until it reaches the Chandrasekhar Limit and collapses under its own mass. As these stars blow off their outer layers in a massive explosion, they temporarily outshine everything in the background.

In a recent study, an international team of researchers led by Ariel Goobar of the Oskar Klein Centre at Stockholm University discovered an unusual Type Ia supernova, SN Zwicky (SN 2022qmx). In an unusual twist, the team observed an “Einstein Cross,” an unusual phenomenon predicted by Einstein’s Theory of General Relativity where the presence of a gravitational lens in the foreground amplifies light from a distant object. This was a major accomplishment for the team since it involved observing two very rare astronomical events that happened to coincide.

May 3, 2023May 5, 2023 by Matt Williams

Gravitational Lensing is Helping to Nail Down Dark Matter

Using the gravitational lensing technique, a team was able to examine how light from distant quasar was affected by intervening small clumps of dark matter. Credit: NASA/ESA/D. Player (STScI)

According to the most widely-accepted cosmological model, the majority of the mass in our Universe (roughly 85%) consists of “Dark Matter.” This elusive, invisible mass is theorized to interact with “normal” (or “visible”) matter through gravity alone and not electromagnetic fields, neither absorbing nor emitting light (hence the name “dark”). The search for this matter is ongoing, with candidate particles including Weakly-Interacting Massive Particles (WIMPs) or ultralight bosons (axions), which are at opposite extremes of the mass scale and behave very differently (in theory).

This matter’s existence is essential for our predominant theories of gravity (General Relativity) and particle physics (The Standard Model) to make sense. Otherwise, we may need to radically rethink our theories on how gravity behaves on the largest of scales (aka. Modified Gravity). However, according to new research led by the University of Hong Kong (HKU), the study of “Einstein Rings” could bring us a step closer to understanding Dark Matter. According to their paper, the way Dark Matter alters the curvature of spacetime leaves signatures that suggest it could be made up of axions!