Skip to main content

Hubble spots cocoon of gas protecting galaxy for the first time

Our Milky Way galaxy isn’t alone in our corner of the universe — as well as the millions of distant galaxies out there, we have two nearby neighbors. The Large and Small Magellanic Clouds are small satellite galaxies, bound to our galaxy by gravity and orbiting around it.

The forces these galaxies experience are enormous, with the gravitational force the Milky Way exerts yanking at them, but despite this, they have somehow stayed intact over billions of years. Now, research using the Hubble Space Telescope explains how this happened, revealing a protective shield that has kept these smaller galaxies safe.

The Magellanic Corona, a diffuse halo of hot, supercharged gas surrounding the Small and Large Magellanic Clouds, shown in purple.
Researchers have used spectroscopic observations of ultraviolet light from quasars to detect and map the Magellanic Corona, a diffuse halo of hot, supercharged gas surrounding the Small and Large Magellanic Clouds. Shown in purple, the corona stretches more than 100,000 light-years from the main mass of stars, gas, and dust that make up the Magellanic Clouds, intermingling with the hotter and more extensive corona that surrounds the Milky Way. ILLUSTRATION: NASA, ESA, Leah Hustak (STScI)

The protective shield, known as a corona, is made up of hot supercharged gas and surrounds the Magellanic clouds. This keeps gas within the galaxies, which is vital as it is what allows them to continue to form new stars. Stretching 100,000 light-years from the dwarf galaxies, the corona has prevented the more massive Milky Way from pulling away all of its gas. “Galaxies envelop themselves in gaseous cocoons, which act as defensive shields against other galaxies,” explained one of the researchers, Andrew Fox of the Space Telescope Science Institute, in a statement.

These shield structures had been theorized by astronomers before but had never been observed because they are very hard to see. The researchers had to dig through archival Hubble data to look at quasars, which are extremely bright. They are so bright that they make the shield visible as a haze, and by looking at 28 quasars the researchers could identify the corona. They saw more gas around the center of the Large Magellanic Cloud, which tapers off toward its edges.

“It’s a perfect telltale signature that this corona is really there,” said Krishnarao. “It really is cocooning the galaxy and protecting it.”

The research is published in the journal Nature.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble captures a busy frame of four overlapping spiral galaxies
This image from the NASA/ESA Hubble Space Telescope features a richness of spiral galaxies.

This week's image from the Hubble Space Telescope shows a host of galaxies overlapping in a complex swirl. Four main galaxies are shown in the image, three of which look like they are practically on top of each other, but all is not as it appears in this case.

The largest galaxy in the image, located on the right, is NGC 1356, an elegant barred spiral galaxy similar to our Milky Way. It is also known as the Great Barred Spiral Galaxy due to the prominent nature of its bar, which is a bright structure at the center of the galaxy which is rich with stars. Near this galaxy appear two smaller spiral galaxies, LEDA 467699 and LEDA 95415, and off on the left side of the image is IC 1947.

Read more
Hubble snaps an image of dark spokes in Saturn’s rings
This photo of Saturn was taken by NASA's Hubble Space Telescope on October 22, 2023, when the ringed planet was approximately 850 million miles from Earth. Hubble's ultra-sharp vision reveals a phenomenon called ring spokes. Saturn's spokes are transient features that rotate along with the rings. Their ghostly appearance only persists for two or three rotations around Saturn. During active periods, freshly-formed spokes continuously add to the pattern.

The Hubble Space Telescope is investigating something strange about the beautiful rings around Saturn. You might picture Saturn's rings as perfectly smooth, but in fact, they have some strange dark spots that appear intermittently. These features, called spokes, look like dusty blots spread over the rings and appear for just a few rotations before disappearing again, with some periods having much more spoke activity than others.

These spokes were first observed over 40 years ago by the Voyager 2 spacecraft, but they continue to be something of a mystery. They seem to be linked to seasons on the planet, which are seven years long, and to the planet's magnetic field. A newly released image taken by Hubble in October this year shows the spokes as dark patches on the rings, observed as part of a program called Hubble's Outer Planets Atmospheres Legacy (OPAL), which tracks them as they move.

Read more
Hubble gets festive with a string of cosmic Christmas lights
The billion stars in galaxy UGC 8091 resemble a sparkling snow globe in this festive Hubble Space Telescope image from NASA and ESA (European Space Agency). The dwarf galaxy is approximately 7 million light-years from Earth in the constellation Virgo. It is considered an "irregular galaxy" because it does not have an orderly spiral or elliptical appearance. Instead, the stars that make up this celestial gathering look more like a brightly shining tangle of string lights than a galaxy.

Researchers using the Hubble Space Telescope are getting into the festive spirit with a holiday image showing a dwarf irregular galaxy called UGC 8091. Located 7 million light-years away in the constellation of Virgo, this region is a hotbed of star formation, with bright young stars illuminating the gas around them to create a sparkling mass reminiscent of Christmas lights.

It is designated an irregular galaxy because of its nonuniform shape, and a dwarf galaxy because of its small size. Unlike spiral galaxies, such as our Milky Way, or elliptical galaxies, which are smooth and have a elliptical shape, irregular galaxies can come in a variety of shapes. Often, these galaxies have been pulled into odd shapes due to gravitational forces, such as when two galaxies come close to each other and interact.

Read more