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.

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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.

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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.

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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.

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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.

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Hubble Pins Down the Mass of a Potential Free-Floating Black Hole That’s 5,000 Light-Years Away

This is an artist’s impression of a black hole drifting through our Milky Way galaxy. The black hole is the crushed remnant of a massive star that exploded as a supernova. The surviving core is several times the mass of our Sun. The black hole traps light because of its intense gravitational field. The black hole distorts the space around it, which warps images of background stars lined up almost directly behind it. This gravitational "lensing" effect offers the only telltale evidence for the existence of lone black holes wandering our galaxy, of which there may be a population of 100 million. The Hubble Space Telescope goes hunting for these black holes by looking for distortion in starlight as the black holes drift in front of background stars. Credit: ESA

Earlier this year, astronomers used microlensing and the Hubble Space Telescope to detect, for the first time, a rogue black hole that is about 5,000 lightyears away from Earth. Now, with more precise measurements, they have been able to determine an approximate mass of this hard-to-detect object. However, the surprisingly low mass means there’s a chance this object may not actually be a black hole.

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We can Probably Find Supernovae Enhanced by Gravitational Lensing, We Just Need to Look

Using the microlensing metthod, a team of astrophysicists have found the first extra-galactic planets! Credit: NASA/Tim Pyle

Gravitational lensing provides an opportunity to see supernovae and other transients much farther than we normally can. A new research proposal outlines a plan to use a comprehensive catalog of strong gravitational lenses to capture these rare events at extreme distances.

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A Gravitational Lens Shows the Same Galaxy Three Times

This star- and galaxy-studded image was captured by Hubble’s Wide Field Camera 3 (WFC3). The galaxy visible in the bottom right corner of the image, named SGAS 0033+02 is a triple gravitational lens. Credit: ESA/Hubble & NASA, E. Wuyts.

Images from the Hubble Space Telescope are often mind-bending in both their beauty and wealth of scientific wonder. And sometimes, Hubble captures light-bending images too.

Hubble’s Wide Field Camera 3 (WFC3) snapped a photo of a galaxy where the light has been bent by gravitational lensing, so that the galaxy show up not just once, but three times. But the multiple views aren’t exact replicas of each other — they appear as different shapes.

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What a Perfect Gravitational Lens

Clustered at the centre of this image are six luminous spots of light, four of them forming a circle around a central pair. Credit: ESA/Hubble & NASA, Acknowledgment: J. Schmidt

A stunning new photograph from the Hubble Space Telescope shows a nearly perfect Einstein Ring, an effect caused by gravitational lensing. This is one of the most complete Einstein Rings ever seen.

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Gaia Finds 12 Examples of Einstein Crosses; Galaxies Being Gravitationally Lensed so we see Them Repeated 4 Times

Credit and : R. Hurt (IPAC/Caltech)/The GraL Collaboration

In 1915, Einstein put the finishing touches on his Theory of General Relativity (GR), a revolutionary new hypothesis that described gravity as a geometric property of space and time. This theory remains the accepted description of gravitation in modern physics and predicts that massive objects (like galaxies and galaxy clusters) bend the very fabric of spacetime.

As result, massive objects (like galaxies and galaxy clusters) can act as a lens that will deflect and magnify light coming from more distant objects. This effect is known as “gravitational lensing,” and can result in all kinds of visual phenomena – not the least of which is known as an “Einstein Cross.” Using data from the ESA’s Gaia Observatory, a team of researchers announced the discovery of 12 new Einstein Crosses.

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