Skip to main content

Hubble captures an aging galaxy that is slowly fading away

This unusual lenticular galaxy, which is between a spiral and elliptical shape, has lost almost all the gas and dust from its signature spiral arms, which used to orbit around its center. Known as NGC 1947, this galaxy was discovered almost 200 years ago by James Dunlop, a Scottish-born astronomer who later studied the sky from Australia. NGC 1947 can only be seen from the southern hemisphere, in the constellation Dorado (the Dolphinfish).
This unusual lenticular galaxy, which is between a spiral and elliptical shape, has lost almost all the gas and dust from its signature spiral arms, which used to orbit around its center. Known as NGC 1947, this galaxy was discovered almost 200 years ago by James Dunlop, a Scottish-born astronomer who later studied the sky from Australia. NGC 1947 can only be seen from the southern hemisphere, in the constellation Dorado (the Dolphinfish). ESA/Hubble & NASA, D. Rosario; Acknowledgment: L. Shatz

The Hubble Space Telescope has captured this beautiful image of a lenticular galaxy called NGC 1947. A lenticular galaxy is one that is neither a spiral galaxy, like our Milky Way, nor an elliptical galaxy, but somewhere in between the two. It has a large disk in the middle but unlike other spiral galaxies, it does not have spiral arms reaching out from its center.

This galaxy wasn’t always this way, however. At a point in its past, it did have spiral arms. You can see the evidence of these arms in the swirls of dust which still surround it, as the European Space Agency writes: “the faint remnants of the galaxy’s spiral arms can still be made out in the stretched thin threads of dark gas encircling it.”

Another difference between lenticular galaxies like NGC 1947 and other kinds of galaxy is the rate of star formation. Galaxies like the Milky Way continue to form new stars, especially in their spiral arms, as clouds of dust and gas clump together and are eventually bound by gravitational forces. In lenticular galaxies, however, there is very little star formation. These galaxies have used up most of their interstellar matter so there is not enough material for the formation of many new stars.

This means that the average age of stars in NGC 1947 is getting older, and the galaxy is fading over time. To see the galaxy for yourself, you’d need to be located in the southern hemisphere as it is further south than the celestial equator.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble spies baby stars being born amid chaos of interacting galaxies
Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, seen in this Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. They form when knots of gas gravitationally collapse to create about 1 million newborn stars per cluster.

When two galaxies collide, the results can be destructive, with one of the galaxies ending up ripped apart, but it can also be constructive too. In the swirling masses of gas and dust pulled around by the gravitational forces of interacting galaxies, there can be bursts of star formation, creating new generations of stars. The Hubble Space Telescope recently captured one such hotbed of star formation in galaxy AM 1054-325, which has been distorted into an unusual shape due to the gravitational tugging of a nearby galaxy.

Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, as seen in this Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. NASA, ESA, STScI, Jayanne English (University of Manitoba)

Read more
Small exoplanet could be hot and steamy according to Hubble
This is an artist’s conception of the exoplanet GJ 9827d, the smallest exoplanet where water vapour has been detected in its atmosphere. The planet could be an example of potential planets with water-rich atmospheres elsewhere in our galaxy. It is a rocky world, only about twice Earth’s diameter. It orbits the red dwarf star GJ 9827. Two inner planets in the system are on the left. The background stars are plotted as they would be seen to the unaided eye looking back toward our Sun, which itself is too faint to be seen. The blue star at upper right is Regulus, the yellow star at bottom centre is Denebola, and the blue star at bottom right is Spica. The constellation Leo is on the left, and Virgo is on the right. Both constellations are distorted from our Earth-bound view from 97 light-years away.

One of the big topics in exoplanet research right now is not just finding exoplanets but also looking at their atmospheres. Tools like the James Webb Space Telescope are designed to allow researchers to look at the light coming from distant stars and see how it is filtered as it passes by exoplanets, allowing them to learn about the composition of their atmospheres. But scientists are also using older telescopes like the Hubble Space Telescope for similar research -- and Hubble recently identified water vapor in an exoplanet atmosphere.

“This would be the first time that we can directly show through an atmospheric detection that these planets with water-rich atmospheres can actually exist around other stars,” said researcher Björn Benneke of the Université de Montréal in a statement. “This is an important step toward determining the prevalence and diversity of atmospheres on rocky planets."

Read more
Hear the otherworldly sounds of interacting galaxies with this Hubble sonification
This new NASA Hubble Space Telescope image showcases a resplendent pair of galaxies known as Arp 140.

When two different galaxies get close enough together that they begin interacting, they are sometimes given a shared name. That's the case with a newly released image from the Hubble Space Telescope that shows two galaxies, NGC 274 and NGC 275, which are together known as Arp 140. not only is there a new image of the pair, but there's also a sonification available so you can hear the image as well as see it.

This new NASA Hubble Space Telescope image showcases a resplendent pair of galaxies known as Arp 140. NASA/ESA/R. Foley (University of California - Santa Cruz)/Processing: Gladys Kober (NASA/Catholic University of America)

Read more