Skip to main content

Hubble captures a dusty galaxy that holds a luminous secret

The image from the Hubble Space Telescope this week shows the dusty galaxy NGC 7172, located 110 million light-years away in the constellation of Piscis Austrinus (the southern fish). This might look like a typical galaxy from this angle, but in fact, it holds a secret.

“The lane of dust threading its way across NGC 7172 is obscuring the luminous heart of the galaxy, making NGC 7172 appear to be nothing more than a normal spiral galaxy viewed from the side,” Hubble scientists write. However, on closer inspection astronomers found something unexpected: “When astronomers inspected NGC 7172 across the electromagnetic spectrum they quickly discovered that there was more to it than meets the eye: NGC 7172 is a Seyfert galaxy — a type of galaxy with an intensely luminous active galactic nucleus powered by matter accreting onto a supermassive black hole.”

Tendrils of dark dust threading across the heart of the spiral galaxy NGC 7172.
This image from the NASA/ESA Hubble Space Telescope reveals tendrils of dark dust threading across the heart of the spiral galaxy NGC 7172. The galaxy lies approximately 110 million light-years from Earth in the constellation Piscis Austrinus. ESA/Hubble & NASA, D. J. Rosario, A. Barth; Acknowledgment: L. Shatz

Hubble views objects like this galaxy in the visible light wavelength, which is the same as what the human eye can see. This image was taken using two of its instruments, the Advanced Camera for Surveys and Wide Field Camera 3.

Recommended Videos

To understand more about the structure of this galaxy, though, it was necessary to look through a different wavelength. In the 1980s astronomers observed the galaxy in the infrared wavelength, which can look through clouds of dust to observe structures beneath. Observations at these wavelengths revealed the brightly glowing heart of the Seyfert galaxy.

The Hubble image uses data collected for a study of active galactic nuclei, a group that includes Seyfert galaxies. Active galactic nuclei are brightly-glowing regions at the heart of galaxies that seem to be brighter than can be accounted for due to the density of stars there. These regions can be so bright that they are brighter than the entire rest of the galaxy.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Hubble spots a cosmic bullseye: a galaxy with nine rings
LEDA 1313424, aptly nicknamed the Bullseye, is two and a half times the size of our Milky Way and has nine rings — six more than any other known galaxy. High-resolution imagery from NASA’s Hubble Space Telescope confirmed eight rings, and data from the W. M. Keck Observatory in Hawaii confirmed a ninth. Hubble and Keck also confirmed which galaxy dove through the Bullseye, creating these rings: the blue dwarf galaxy that sits to its immediate center-left.

The Hubble Space Telescope has captured this striking image of an unusual galaxy with a bullseye structure, as nine rings surround its central point. Technically known as LEDA 1313424, the galaxy has more rings than any other known galaxy, and studying it is helping astronomers to learn how galaxies like this are created.

Along with the W. M. Keck Observatory in Hawai'i, astronomers used Hubble to see that there was not just one ring around this galaxy but many. "This was a serendipitous discovery," said lead researcher Imad Pashaof Yale University. "I was looking at a ground-based imaging survey and when I saw a galaxy with several clear rings, I was immediately drawn to it. I had to stop to investigate it."

Read more
Hubble snaps another gorgeous image of the Tarantula Nebula
This NASA/ESA Hubble Space Telescope image features a dusty yet sparkling scene from one of the Milky Way’s satellite galaxies, the Large Magellanic Cloud. The Large Magellanic Cloud is a dwarf galaxy situated about 160,000 light-years away in the constellations Dorado and Mensa.

This gorgeous new image from the Hubble Space Telescope shows a bustling nearby star forming region called the Tarantula Nebula. Given its name due to its complex, web-like internal structure, this nebula is located in a satellite galaxy of the Milky Way called the Large Magellanic Cloud and is often studied by astronomers researching star formation and evolution.

This new image shows the edges of the nebula, further out from its center. In the middle of the nebula are enormous stars that are as much as 200 times the mass of the sun, but here on the outskirts the view is calmer.

Read more
Feast your eyes on 10 years of Hubble images of Jupiter, Saturn, Uranus, Neptune
This is a montage of NASA/ESA Hubble Space Telescope views of our solar system's four giant outer planets: Jupiter, Saturn, Uranus, and Neptune, each shown in enhanced color. The images were taken over nearly 10 years, from 2014 to 2024.

While the Hubble Space Telescope might be most famous for its images of beautiful and far-off objects like nebulae or distant galaxies, it also takes images of objects closer to home, including the planets right here in our own solar system. For the past 10 years, Hubble has been studying the outer planets in a project called OPAL (Outer Planet Atmospheres Legacy), capturing regular images of each of the four outer planets so scientists can study their changes over time.

The planets Jupiter, Saturn, Uranus, and Neptune are different in many ways from Earth, as they are gas giants and ice giants rather than rocky planets. But they do have some similar phenomena, such as weather that regularly changes, including epic events like storms that are so large they can be seen from space. Jupiter's Great Red Spot, for example, the big orange-red eye shape that is visible on most images of the planet, is an enormous storm larger than the width of the entire Earth and which has been raging for centuries.

Read more