Space and Science

Newly discovered giant galaxies dwarf the Milky Way

Ashley Strickland
By Ashley Strickland, CNN
Published 2:52 PM EST, Thu January 21, 2021
This illustration shows a massive star on the brink of explosion.
This illustration shows a massive star on the brink of explosion.
Chuck Carter/Caltech
Meet the fastest asteroid in our solar system, which zips around the sun every 113 days. This artist's rendering shows the asteroid 2021 PH27 (top right) and Mercury (below) orbiting the sun.
Meet the fastest asteroid in our solar system, which zips around the sun every 113 days. This artist's rendering shows the asteroid 2021 PH27 (top right) and Mercury (below) orbiting the sun.
CTIO/NOIRLab/NSF/AURA/J. da Silva
A ghostly set of X-ray rings were found around a black hole with a companion star. These rings are created by light echoes.
A ghostly set of X-ray rings were found around a black hole with a companion star. These rings are created by light echoes.
CXC/U.Wisc-Madison/S. Heinz et al./Pan-STARRS/NASA
This image, taken with the Atacama Large Millimeter/submillimeter Array in Chile, shows the PDS 70 system 400 light-years away. This planetary system is still forming and still in the process of being formed. One of the planets in the system has a moon-forming disk around it.
This image, taken with the Atacama Large Millimeter/submillimeter Array in Chile, shows the PDS 70 system 400 light-years away. This planetary system is still forming and still in the process of being formed. One of the planets in the system has a moon-forming disk around it.
ALMA/ESO/NAOJ/NRAO/Benisty et al.
This image shows supernova 2018zd (pictured as the large white dot on the right), a new type of supernova called an electron capture. To the left is the galaxy NGC 2146.
This image shows supernova 2018zd (pictured as the large white dot on the right), a new type of supernova called an electron capture. To the left is the galaxy NGC 2146.
NASA/STSCI/J. Depasquale; Las Cumbres Observatory
This image from the STARFORGE simulation shows the "Anvil of Creation," a giant gas cloud with individual stars forming inside of it.
This image from the STARFORGE simulation shows the "Anvil of Creation," a giant gas cloud with individual stars forming inside of it.
From Northwestern University/UT Austin
Astronomers used NASA's Chandra X-ray Observatory to study the supernova remnant Cassiopeia A and discovered titanium, shown in light blue, blasting out of it. The colors represent other elements detected, like iron (orange), oxygen (purple), silicon (red) and magnesium (green).
Astronomers used NASA's Chandra X-ray Observatory to study the supernova remnant Cassiopeia A and discovered titanium, shown in light blue, blasting out of it. The colors represent other elements detected, like iron (orange), oxygen (purple), silicon (red) and magnesium (green).
T. Sato et al./RIKEN/CXC/NASA
The supermassive black hole at the center of the M87 galaxy, the first to ever be imaged, can now be seen in polarized light. Swirling lines reveal the magnetic field near the edge of the black hole.
The supermassive black hole at the center of the M87 galaxy, the first to ever be imaged, can now be seen in polarized light. Swirling lines reveal the magnetic field near the edge of the black hole.
European Southern Observatory
This image from the Sloan Digital Sky Survey shows the galaxy J0437+2456, which includes a supermassive black hole at its center that appears to be moving.
This image from the Sloan Digital Sky Survey shows the galaxy J0437+2456, which includes a supermassive black hole at its center that appears to be moving.
Sloan Digital Sky Survey
This artist's impression shows how the distant quasar P172+18 and its radio jets may have looked 13 billion years ago. The light from the quasar has taken that long to reach us, so astronomers observed the quasar as it looked in the early universe.
This artist's impression shows how the distant quasar P172+18 and its radio jets may have looked 13 billion years ago. The light from the quasar has taken that long to reach us, so astronomers observed the quasar as it looked in the early universe.
M. Kornmesser/European Southern Observatory
This image shows the vicinity of the Tucana II ultrafaint dwarf galaxy, captured by the SkyMapper telescope.
This image shows the vicinity of the Tucana II ultrafaint dwarf galaxy, captured by the SkyMapper telescope.
Anirudh Chiti/MIT
These images show two giant radio galaxies found with using the MeerKAT telescope. The red in both images shows the radio light being emitted by the galaxies against a background of the sky as it is seen in visible light.
These images show two giant radio galaxies found with using the MeerKAT telescope. The red in both images shows the radio light being emitted by the galaxies against a background of the sky as it is seen in visible light.
I. Heywood/Oxford/Rhodes/SARAO
This artist's conception of quasar J0313-1806 depicts it as it was 670 million years after the Big Bang. Quasars are highly energetic objects at the centers of galaxies, powered by black holes and brighter than entire galaxies.
This artist's conception of quasar J0313-1806 depicts it as it was 670 million years after the Big Bang. Quasars are highly energetic objects at the centers of galaxies, powered by black holes and brighter than entire galaxies.
NOIRLab/NSF/AURA/J. da Silva
Shown here is a phenomenon known as zodiacal light, which is caused by sunlight reflecting off tiny dust particles in the inner solar system.
Shown here is a phenomenon known as zodiacal light, which is caused by sunlight reflecting off tiny dust particles in the inner solar system.
Zolt Levay/Space Telescope Science Institute
This artist's impression of the distant galaxy ID2299 shows some of its gas being ejected by a "tidal tail" as a result of a merger between two galaxies.
This artist's impression of the distant galaxy ID2299 shows some of its gas being ejected by a "tidal tail" as a result of a merger between two galaxies.
M. Kornmesser/ESO
This diagram shows the two most important companion galaxies to the Milky Way: the Large Magellanic Cloud (left) and the Small Magellanic Cloud. It was made using data from the European Space Agency Gaia satellite.
This diagram shows the two most important companion galaxies to the Milky Way: the Large Magellanic Cloud (left) and the Small Magellanic Cloud. It was made using data from the European Space Agency Gaia satellite.
Laurent Chemin/ESA/Gaia/DPAC
The Blue Ring Nebula is thought to be a never-before-seen phase that occurs after the merger of two stars. Debris flowing out from the merger was sliced by a disk around one of the stars, creating two cones of material glowing in ultraviolet light.
The Blue Ring Nebula is thought to be a never-before-seen phase that occurs after the merger of two stars. Debris flowing out from the merger was sliced by a disk around one of the stars, creating two cones of material glowing in ultraviolet light.
NASA/JPL-Caltech/M. Seibert/K. Hoadley/GALEX Team
The red supergiant star Betelgeuse, in the constellation of Orion, experienced unprecedented dimming late in 2019. This image was taken in January using the European Southern Observatory's Very Large Telescope.
The red supergiant star Betelgeuse, in the constellation of Orion, experienced unprecedented dimming late in 2019. This image was taken in January using the European Southern Observatory's Very Large Telescope.
ESO/M. Montargès et al.
This is an infrared image of Apep, a Wolf-Rayet star binary system located 8,000 light-years from Earth.
This is an infrared image of Apep, a Wolf-Rayet star binary system located 8,000 light-years from Earth.
European Southern Observatory
An artist's illustration, left, helps visualize the details of an unusual star system, GW Orionis, in the Orion constellation. The system's circumstellar disk is broken, resulting in misaligned rings around its three stars.
An artist's illustration, left, helps visualize the details of an unusual star system, GW Orionis, in the Orion constellation. The system's circumstellar disk is broken, resulting in misaligned rings around its three stars.
ESO/L. Calçada, Exeter/Kraus et al.
This is a simulation of two spiral black holes that merge and emit gravitational waves.
This is a simulation of two spiral black holes that merge and emit gravitational waves.
N. Fischer, H. Pfeiffer, A. Buonanno, MPIGP, SXS Collaboration
This artist's illustration shows the unexpected dimming of the star Betelgeuse.
This artist's illustration shows the unexpected dimming of the star Betelgeuse.
ESO, ESA/Hubble, M. Kornmesser
This extremely distant galaxy, which looks similar to our own Milky Way, appears like a ring of light.
This extremely distant galaxy, which looks similar to our own Milky Way, appears like a ring of light.
Rizzo et al./ALMA/European Southern Observatory
This artist's interpretation shows the calcium-rich supernova 2019ehk. The orange represents the calcium-rich material created in the explosion. Purple reveals gas shed by the star right before the explosion.
This artist's interpretation shows the calcium-rich supernova 2019ehk. The orange represents the calcium-rich material created in the explosion. Purple reveals gas shed by the star right before the explosion.
Aaron M. Geller, Northwestern University
The blue dot at the center of this image marks the approximate location of a supernova event which occurred 140 million light-years from Earth, where a white dwarf exploded and created an ultraviolet flash. It was located close to tail of the Draco constellation.
The blue dot at the center of this image marks the approximate location of a supernova event which occurred 140 million light-years from Earth, where a white dwarf exploded and created an ultraviolet flash. It was located close to tail of the Draco constellation.
Northwestern University
This radar image captured by NASA's Magellan mission to Venus in 1991 shows a corona, a large circular structure 120 miles in diameter, named Aine Corona.
This radar image captured by NASA's Magellan mission to Venus in 1991 shows a corona, a large circular structure 120 miles in diameter, named Aine Corona.
From NASA/JPL
When a star's mass is ejected during a supernova, it expands quickly. Eventually, it will slow and form a hot bubble of glowing gas. A white dwarf will emerge from this gas bubble and move across the galaxy.
When a star's mass is ejected during a supernova, it expands quickly. Eventually, it will slow and form a hot bubble of glowing gas. A white dwarf will emerge from this gas bubble and move across the galaxy.
Mark Garlick/University of Warwick
The afterglow of short gamma ray burst that was detected 10 billion light-years away is shown here in a circle. This image was taken by the Gemini-North telescope.
The afterglow of short gamma ray burst that was detected 10 billion light-years away is shown here in a circle. This image was taken by the Gemini-North telescope.
International Gemini Observatory/K. Paterson/W. Fong/Northwestern University
This Hubble Space Telescope image shows NGC 7513, a barred spiral galaxy 60 million light-years away. Due to the expansion of the universe, the galaxy appears to be moving away from the Milky Way at an accelerate rate.
This Hubble Space Telescope image shows NGC 7513, a barred spiral galaxy 60 million light-years away. Due to the expansion of the universe, the galaxy appears to be moving away from the Milky Way at an accelerate rate.
Hubble Space Telescope/NASA/ESA/M. Stiavelli
This artist's concept illustration shows what the luminous blue variable star in the Kinman Dwarf galaxy may have looked like before it mysteriously disappeared.
This artist's concept illustration shows what the luminous blue variable star in the Kinman Dwarf galaxy may have looked like before it mysteriously disappeared.
L. Calçada/ESO
This is an artist's illustration of a supermassive black hole and its surrounding disk of gas. Inside this disk are two smaller black holes orbiting one another. Researchers identified a flare of light suspected to have come from one such binary pair soon after they merged into a larger black hole.
This is an artist's illustration of a supermassive black hole and its surrounding disk of gas. Inside this disk are two smaller black holes orbiting one another. Researchers identified a flare of light suspected to have come from one such binary pair soon after they merged into a larger black hole.
Robert Hurt/California Institute of Technology
This image, taken from a video, shows what happens as two objects of different masses merge together and create gravitational waves.
This image, taken from a video, shows what happens as two objects of different masses merge together and create gravitational waves.
Max Planck Institute for Gravitational Physics/Simulating eXtreme Spacetimes (SXS) Collaboration
This is an artist's impression showing the detection of a repeating fast radio burst seen in blue, which is in orbit with an astrophysical object seen in pink.
This is an artist's impression showing the detection of a repeating fast radio burst seen in blue, which is in orbit with an astrophysical object seen in pink.
Kristi Mickaliger
Fast radio bursts, which make a splash by leaving their host galaxy in a bright burst of radio waves, helped detect "missing matter" in the universe.
Fast radio bursts, which make a splash by leaving their host galaxy in a bright burst of radio waves, helped detect "missing matter" in the universe.
ICRAR
A new type of explosion was found in a tiny galaxy 500 million light-years away from Earth. This type of explosion is referred to as a fast blue optical transient.
A new type of explosion was found in a tiny galaxy 500 million light-years away from Earth. This type of explosion is referred to as a fast blue optical transient.
Giacomo Terreran/Northwestern University
Astronomers have discovered a rare type of galaxy described as a "cosmic ring of fire." This artist's illustration shows the galaxy as it existed 11 billion years ago.
Astronomers have discovered a rare type of galaxy described as a "cosmic ring of fire." This artist's illustration shows the galaxy as it existed 11 billion years ago.
James Josephides/Swinburne Astronomy Productions
This is an artist's impression of the Wolfe Disk, a massive rotating disk galaxy in the early universe.
This is an artist's impression of the Wolfe Disk, a massive rotating disk galaxy in the early universe.
NRAO/AUI/NSF, S. Dagnello
A bright yellow "twist" near the center of this image shows where a planet may be forming around the AB Aurigae star. The image was captured by the European Southern Observatory's Very Large Telescope.
A bright yellow "twist" near the center of this image shows where a planet may be forming around the AB Aurigae star. The image was captured by the European Southern Observatory's Very Large Telescope.
ESO/Boccaletti et al.
This artist's illustration shows the orbits of two stars and an invisible black hole 1,000 light-years from Earth. This system includes one star (small orbit seen in blue) orbiting a newly discovered black hole (orbit in red), as well as a third star in a wider orbit (also in blue).
This artist's illustration shows the orbits of two stars and an invisible black hole 1,000 light-years from Earth. This system includes one star (small orbit seen in blue) orbiting a newly discovered black hole (orbit in red), as well as a third star in a wider orbit (also in blue).
European Southern Observatory/ESO/L. Calçada
This illustration shows a star's core, known as a white dwarf, pulled into orbit around a black hole. During each orbit, the black hole rips off more material from the star and pulls it into a glowing disk of material around the black hole. Before its encounter with the black hole, the star was a red giant in the last stages of stellar evolution.
This illustration shows a star's core, known as a white dwarf, pulled into orbit around a black hole. During each orbit, the black hole rips off more material from the star and pulls it into a glowing disk of material around the black hole. Before its encounter with the black hole, the star was a red giant in the last stages of stellar evolution.
NASA/CXO/CSIC-INTA/G.Miniutti et al./CXC/M. Weiss
This artist's illustration shows the collision of two 125-mile-wide icy, dusty bodies orbiting the bright star Fomalhaut, located 25 light-years away. The observation of the aftermath of this collision was once thought to be an exoplanet.
This artist's illustration shows the collision of two 125-mile-wide icy, dusty bodies orbiting the bright star Fomalhaut, located 25 light-years away. The observation of the aftermath of this collision was once thought to be an exoplanet.
M. Kornmesser/ESA/NASA
This is an artist's impression of the interstellar comet 2I/Borisov as it travels through our solar system. New observations detected carbon monixide in the cometary tail as the sun heated the comet.
This is an artist's impression of the interstellar comet 2I/Borisov as it travels through our solar system. New observations detected carbon monixide in the cometary tail as the sun heated the comet.
NRAO/AUI/NSF/S. Dagnello
This rosette pattern is the orbit of a star, called S2, around the supermassive black hole at the center of our Milky Way galaxy.
This rosette pattern is the orbit of a star, called S2, around the supermassive black hole at the center of our Milky Way galaxy.
European Southern Observatory/ESO/L. Calçada
This is an artist's illustration of SN2016aps, which astronomers believe is the brightest supernova ever observed.
This is an artist's illustration of SN2016aps, which astronomers believe is the brightest supernova ever observed.
M. Weiss/Center for Astrophysics | Harvard & Smithsonian
This is an artist's illustration of a brown dwarf, or a "failed star" object, and its magnetic field. The brown dwarf's atmosphere and magnetic field rotate at different speeds, which allowed astronomers to determine wind speed on the object.
This is an artist's illustration of a brown dwarf, or a "failed star" object, and its magnetic field. The brown dwarf's atmosphere and magnetic field rotate at different speeds, which allowed astronomers to determine wind speed on the object.
Bill Saxton, NRAO/AUI/NSF
This artist's illustration shows an intermediate-mass black hole tearing into a star.
This artist's illustration shows an intermediate-mass black hole tearing into a star.
M. Kornmesser/ESA/Hubble
This is an artist's impression of a large star known as HD74423 and its much smaller red dwarf companion in a binary star system. The large star appears to pulsate on one side only, and it's being distorted by the gravitational pull of its companion star into a teardrop shape.
This is an artist's impression of a large star known as HD74423 and its much smaller red dwarf companion in a binary star system. The large star appears to pulsate on one side only, and it's being distorted by the gravitational pull of its companion star into a teardrop shape.
Gabriel Pérez Díaz/Institute of Astrophysics of the Canary Islands
This is an artist's impression of two white dwarfs in the process of merging. While astronomers expected that this might cause a supernova, they have found an instance of two white dwarf stars that survived merging.
This is an artist's impression of two white dwarfs in the process of merging. While astronomers expected that this might cause a supernova, they have found an instance of two white dwarf stars that survived merging.
University of Warwick/Mark Garlick
A combination of space and ground-based telescopes have found evidence for the biggest explosion seen in the universe. The explosion was created by a black hole located in the Ophiuchus cluster's central galaxy, which has blasted out jets and carved a large cavity in the surrounding hot gas.
A combination of space and ground-based telescopes have found evidence for the biggest explosion seen in the universe. The explosion was created by a black hole located in the Ophiuchus cluster's central galaxy, which has blasted out jets and carved a large cavity in the surrounding hot gas.
S. Giacintucci, et al./NRL/CXC/NASA
This new ALMA image shows the outcome of a stellar fight: a complex and stunning gas environment surrounding the binary star system HD101584.
This new ALMA image shows the outcome of a stellar fight: a complex and stunning gas environment surrounding the binary star system HD101584.
ESO/NAOJ/NRAO/ALMA
NASA's Spitzer Space Telescope captured the Tarantula Nebula in two wavelengths of infrared light. The red represents hot gas, while the blue regions are interstellar dust.
NASA's Spitzer Space Telescope captured the Tarantula Nebula in two wavelengths of infrared light. The red represents hot gas, while the blue regions are interstellar dust.
JPL-Caltech/NASA
A white dwarf, left, is pulling material off of a brown dwarf, right, about 3,000 light-years from Earth.
A white dwarf, left, is pulling material off of a brown dwarf, right, about 3,000 light-years from Earth.
NASA/L. Hustak
This image shows the orbits of the six G objects at the center of our galaxy, with the supermassive black hole indicated with a white cross. Stars, gas and dust are in the background.
This image shows the orbits of the six G objects at the center of our galaxy, with the supermassive black hole indicated with a white cross. Stars, gas and dust are in the background.
Anna Ciurlo/Tuan Do/UCLA Galactic Center Group
After stars die, they expel their particles out into space, which form new stars in turn. In one case, stardust became embedded in a meteorite that fell to Earth. This illustration shows that stardust could flow from sources like the Egg Nebula to create the grains recovered from the meteorite, which landed in Australia.
After stars die, they expel their particles out into space, which form new stars in turn. In one case, stardust became embedded in a meteorite that fell to Earth. This illustration shows that stardust could flow from sources like the Egg Nebula to create the grains recovered from the meteorite, which landed in Australia.
NASA/W. Sparks (STScI)/R. Sahai
The former North Star, Alpha Draconis or Thuban, is circled here in an image of the northern sky.
The former North Star, Alpha Draconis or Thuban, is circled here in an image of the northern sky.
NASA
Galaxy UGC 2885, nicknamed the "Godzilla galaxy," may be the largest one in the local universe.
Galaxy UGC 2885, nicknamed the "Godzilla galaxy," may be the largest one in the local universe.
NASA/ESA/B. Holwerda (University of Louisville)
The host galaxy of a newly traced repeating fast radio burst acquired with the 8-meter Gemini-North telescope.
The host galaxy of a newly traced repeating fast radio burst acquired with the 8-meter Gemini-North telescope.
Danielle Futselaar/artsource.nl
Wonders of the universe
CNN  — 

Our universe may be filled with unseen giants. Astronomers have discovered two giant radio galaxies, which are some of the largest-known objects in the universe. This revelation suggests that the enormous galaxies may be more common than previously believed.

The study published Monday in the Monthly Notices of the Royal Astronomical Society.

Astronomers found the two galaxies in new radio maps that were created using the MeerKAT radio telescope in South Africa.

Radio galaxies, which can be quite common, are brightest in radio wavelengths of light. Centaurus A is a well-known radio galaxy to astronomers. It’s the fifth brightest galaxy in the sky and is about 12 million light-years from Earth.

Centaurus A features a supermassive black hole at its center, which releases powerful jets that flow perpendicularly to the galaxy’s disk – a common structure for radio galaxies.

This composite image shows the Centaurus A galaxy in visible, microwave (orange) and X-ray (blue) light. Long jets expand out from the galaxy's central black hole on either side.
This composite image shows the Centaurus A galaxy in visible, microwave (orange) and X-ray (blue) light. Long jets expand out from the galaxy's central black hole on either side.
NASA/Royal Astronomical Society

Giant radio galaxies, however, are more rare and have jets that exceed 22 times the size of our Milky Way galaxy. The Milky Way is a barred spiral galaxy, which is also fairly common, and looks like it sounds: a spiral-shaped galaxy with a central bar-shaped structure made of stars.

Now, astronomers have found two giant radio galaxies in a rather small patch of sky.

http://www.spitzer.caltech.edu/images/1923-ssc2008-10a-A-Roadmap-to-the-Milky-Way Like early explorers mapping the continents of our globe, astronomers are busy charting the spiral structure of our galaxy, the Milky Way. Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms. This artist's concept illustrates the new view of the Milky Way, along with other findings presented at the 212th American Astronomical Society meeting in St. Louis, Mo. The galaxy's two major arms (Scutum-Centaurus and Perseus) can be seen attached to the ends of a thick central bar, while the two now-demoted minor arms (Norma and Sagittarius) are less distinct and located between the major arms. The major arms consist of the highest densities of both young and old stars; the minor arms are primarily filled with gas and pockets of star-forming activity. The artist's concept also includes a new spiral arm, called the "Far-3 kiloparsec arm," discovered via a radio-telescope survey of gas in the Milky Way. This arm is shorter than the two major arms and lies along the bar of the galaxy. Our sun lies near a small, partial arm called the Orion Arm, or Orion Spur, located between the Sagittarius and Perseus arms.
http://www.spitzer.caltech.edu/images/1923-ssc2008-10a-A-Roadmap-to-the-Milky-Way Like early explorers mapping the continents of our globe, astronomers are busy charting the spiral structure of our galaxy, the Milky Way. Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms. This artist's concept illustrates the new view of the Milky Way, along with other findings presented at the 212th American Astronomical Society meeting in St. Louis, Mo. The galaxy's two major arms (Scutum-Centaurus and Perseus) can be seen attached to the ends of a thick central bar, while the two now-demoted minor arms (Norma and Sagittarius) are less distinct and located between the major arms. The major arms consist of the highest densities of both young and old stars; the minor arms are primarily filled with gas and pockets of star-forming activity. The artist's concept also includes a new spiral arm, called the "Far-3 kiloparsec arm," discovered via a radio-telescope survey of gas in the Milky Way. This arm is shorter than the two major arms and lies along the bar of the galaxy. Our sun lies near a small, partial arm called the Orion Arm, or Orion Spur, located between the Sagittarius and Perseus arms.
NASA/JPL-Caltech

A stream of nearly 500 stars in the Milky Way is actually a family

“We found these giant radio galaxies in a region of sky which is only about 4 times the area of the full Moon,” said Jacinta Delhaize, lead study author and research fellow at the University of Cape Town, in a statement.

“Based on our current knowledge of the density of giant radio galaxies in the sky, the probability of finding two of them in this region is less than 0.0003 per cent. This means that giant radio galaxies are probably far more common than we thought!”

Just because the galaxies are massive doesn’t mean they’re the easiest to spot, which is why astronomers didn’t observe them until now.

“These two galaxies are special because they are amongst the largest giants known, and in the top 10 per cent of all giant radio galaxies,” said Matthew Prescott, study coauthor and research fellow at the University of the Western Cape in South Africa, in a statement.

Artist's conception of the quasar J0313--1806, seen as it was only 670 million years after the Big Bang.
Artist's conception of the quasar J0313--1806, seen as it was only 670 million years after the Big Bang.
NOIRLab/NSF/AURA/J. da Silva

Oldest quasar and supermassive black hole discovered in the distant universe

“They are more than 2 Mega-parsecs across, which is around 6.5 million light years or about 62 times the size of the Milky Way. Yet they are fainter than others of the same size. We suspect that many more galaxies like these should exist, because of the way we think galaxies grow and change over their lifetimes.”

Astronomers still don’t quite understand why only some radio galaxies grow to this massive size. Some believe that the giant radio galaxies are the oldest, which has allowed their radio jets to increase outward over several hundred million years.

If that’s the case, astronomers think there should be more of them in the universe than those they have recorded.

The MeerKAT telescope, located in the Karoo region of South Africa, includes an array of 64 radio dishes and has been operational since July 2018. The powerful telescope is sensitive to faint radio light, which allowed researchers to find the giant radio galaxies.

The MeerKAT telescope is located in South Africa.
The MeerKAT telescope is located in South Africa.
NASA/Royal Astronomical Society

The telescope array is a precursor to an upcoming telescope, the transcontinental Square Kilometer Array, which will begin construction in both South Africa and Australia this year and begin observations in the mid-2020s.

The array will include thousands of dishes and up to a million low-frequency antennas in an effort to build the world’s largest radio telescope. Despite the fact that these dishes and antennas will be in two different parts of the world, together they will create one telescope that has over 1 million square meters of collecting area, meaning that astronomers can survey the entire sky much more quickly than with other telescopes.

It will also exceed the image resolution of the Hubble Space Telescope and image large portions of the sky in sensitive detail.

The Square Kilometer Array may discover more radio galaxies and shed light on how galaxies evolve.

“In the past, this population of galaxies has been hidden from our ‘sight’ by the technical limitations of radio telescopes,” Delhaize said. “However, it is now being revealed thanks to the impressive capabilities of the new generation of telescopes.”

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