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 sees the changing seasons on Jupiter and Uranus
[Jupiter: left] - The forecast for Jupiter is for stormy weather at low northern latitudes. A prominent string of alternating storms is visible, forming a ‘vortex street’ as some planetary astronomers call it. [Uranus: right] - Uranus’s north pole shows a thickened photochemical haze that looks similar to the smog over cities. Several little storms can be seen near the edge of the polar haze boundary. Note: The planets do not appear in this image to scale.

Our planet isn't the only place in the solar system with dramatic weather changes. Other planets in the solar system also experience seasons, depending on their distance from the sun, and that affects their climates. One of the many jobs of the Hubble Space Telescope is to monitor the changing seasons on other planets, particularly the larger outer planets which aren't so often observed. And this week, scientist have released their newest views of Jupiter and Uranus, taken by Hubble and showing seasonal changes on the two planets.

Jupiter is far from the sun, so most of its heat comes not from outside but from within. Jupiter is thought to have a very high core temperature, which may be a result of how it was formed but could also be topped up by processes inside the planet. As this heat escapes from the planet's interior, it affects its atmosphere which contains multiple layers and has unusual features like geometric storms at its poles.

Read more
A sparkling field of stars cluster together in Hubble image
This image shows just a portion of M55, the cluster as a whole appears spherical because the stars’ intense gravitational attraction pulls them together. Hubble’s clear view above Earth’s atmosphere resolves individual stars in this cluster. Ground-based telescopes can also resolve individual stars in M55, but fewer stars are visible.

A sea of stars sparkles in this image from the Hubble Space Telescope. Showing an tremendous cluster of stars called a globular cluster, this view is located in the galaxy Messier 55.

A globular cluster is a group of stars which is tens of thousands or even millions of stars, and which is held together by gravity. That's why these clusters tend to form spherical shapes as the forces of gravity hold the cluster together.

Read more
A small, fuzzy dwarf galaxy in our neighborhood captured by Hubble
UGCA 307 hangs against an irregular backdrop of distant galaxies in this image from the NASA/ESA Hubble Space Telescope. The small galaxy consists of a diffuse band of stars containing red bubbles of gas that mark regions of recent star formation, and lies roughly 26 million light-years from Earth in the constellation Corvus. Appearing as just a small patch of stars, UGCA 307 is a diminutive dwarf galaxy without a defined structure — resembling nothing more than a hazy patch of passing cloud.

This week's image from the Hubble Space Telescope shows a galaxy in our backyard, cosmically speaking, taken as part of a project to image nearby galaxies. Galaxy UGCA 307 is located 26 million light-years away in the constellation of Corvus, or The Crow, a small constellation visible from the southern hemisphere which was documented as far back as 1,000 years BCE.

There is just a small cluster of stars within this galaxy, as it is a type called a dwarf galaxy. These are defined as galaxies with just a few billion stars, which sounds like a lot until you compare it to the hundreds of billions of stars that are found in our galaxy, the Milky Way.

Read more