Skip to main content

Hubble captures a peculiar galaxy pulled out of shape by a nearby satellite

A spiral galaxy named NGC 772, captured by the NASA/ESA Hubble Space Telescope. This image was first shared on 11th November 2019. ESA/Hubble & NASA, A. Seth et al.

This elegant image was captured by the Hubble Space Telescope, showing a galaxy called NGC 772 which is located 130 million light-years away in the constellation Aries.

NGC 772 has some distinctive features. One immediately noticeable difference between NGC 772 and our home galaxy is that it does not have a bar, unlike the Milky Way which is a barred galaxy. Bars are bands of bright light caused by structures of dust and gas which run along the center of galaxies. Astronomers believe these bars typically develop later in the lifetime of most galaxies, and between one-third and two-thirds of all galaxies are thought to have bars.

In the Milky Way and other barred galaxies, bars contribute to star formation by funneling the dust and gases which are the building blocks of stars into the galactic core. In a non-barred galaxy like NGC 772, this mechanism is missing, although there is still plenty of dust and gas floating around for the forming of new stars in other regions of the galaxy.

NGC 772 is also an unusual elongated shape, which means it is technically classified as a “peculiar galaxy.” The peculiarity, in this case, is the spiral arm in the upper portion of the image, which has been stretched and extended. The distortion is caused by the movements of a nearby satellite galaxy, which is a term for a smaller galaxy that is gravitationally bound to a larger galaxy and which orbits around it.

One of NGC 772’s satellite galaxies is called NGC 770, which isn’t visible in the image but does have a visible impact. NGC 770 exerts tidal forces on its larger host galaxy, pulling the one spiral arm out deeper into space. That’s why NGC 772 appears asymmetrical.

Our Milky Way also has satellite galaxies including the Large Magellanic Cloud and Small Magellanic Cloud, although data from Hubble suggests that these galaxies may be moving too fast to truly be in orbit around our galaxy. Eventually, however, these smaller galaxies may cause the demise of our galaxy, as researchers believe the Large Magellanic Cloud will eventually collide with the Milky Way and cause the black hole at the heart of our galaxy to explode in size and devour nearby matter.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble captures an elegant spiral galaxy 60 million light-years away
A stunning view of the spiral galaxy NGC 4571.

This week's image from the Hubble Space Telescope shows the spiral galaxy NGC 4571, located 60 million light-years away in the constellation of Coma Berenices, and was captured using Hubble's Wide Field Camera 3 instrument.

This cosmic portrait – captured with the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 – shows a stunning view of the spiral galaxy NGC 4571, which lies approximately 60 million light-years from Earth in the constellation Coma Berenices. This constellation – whose name translates as Bernice’s Hair – was named after an Egyptian queen who lived more than 2,200 years ago. ESA/Hubble & NASA, J. Lee and the PHANGS-HST Team

Read more
Hubble used two instruments to image this beautiful galaxy
The heart of NGC 1097, a barred spiral galaxy that lies about 48 million light-years from Earth in the constellation Fornax.

This week's image from the Hubble Space Telescope is striking: The beautiful galaxy NCG 1097, as captured using two of Hubble's instruments working in tandem. This barred spiral galaxy is located 48 million light-years away, in the constellation of Fornax, and has a twisted shape caused by gravitational interactions with a nearby companion galaxy called NCG 1097A.

This particular galaxy is known for being the site of no less than three supernovas over the past two decades, with stars exploding in epic events when they reached the ends of their lives. The supernovas were called SN 1992bd, SN 1999eu, and SN 2003B, named for the years of their observations.

Read more
A baby star’s energetic outburst captured by Hubble
An energetic outburst from an infant star streaks across this image from the NASA/ESA Hubble Space Telescope. This stellar tantrum – produced by an extremely young star in the earliest phase of formation – consists of an incandescent jet of gas travelling at supersonic speeds. As the jet collides with material surrounding the still-forming star, the shock heats this material and causes it to glow. The result is the colorfully wispy structures, which astronomers refer to as Herbig–Haro objects, billowing across the lower right of this image.

This week's image from the Hubble Space Telescope shows the dramatic and energetic jets given off by a young star, forming a wispy structure called a Herbig-Haro object. The image shows object HH34, located 1,250 light-years away in the Orion Nebula. The Orion Nebula is a site of active star formation and as it is bright enough to be seen even by the naked eye, it is often studied to learn about the formation of stars.

A Herbig-Haro object is formed when a young, particularly energetic star ejects particles of ionized gas in epic jets. These jets typically eject from opposite sides of the star, illuminating gas and dust around them which glows in beautiful colors. These jets are so powerful they can travel at hundreds of miles per second, meaning they spread far beyond the star and form these long, thin shapes which can be seen from great distances.

Read more