Three-hundred and sixty million years ago, elliptical galaxy NGC 5291 was impacted by a fast-moving galaxy that drove into its core. Huge gas streams were sent shooting off into surrounding space, eventually gathering to form a ring around NGC 5291. Scientists from the European Southern Observatory (ESO) have taken new images of this galaxy with the Very Large Telescope located at the Paranal Observatory.
But among the surrounding stellar debris astronomers discovered an unusual young dwarf galaxy, which they’ve dubbed NGC 5291N.
According to the ESO, NGC 5291B formed when material in the surrounding ring coalesced and collapsed into a handful of star-forming regions and several dwarf galaxies. In the new image, NGC 5291 sits center, a bright burning oval. The new dwarf galaxies are the blue and white regions peppered around it. NGC 5291B is among the largest dwarf galaxies in the vicinity.
Dwarf galaxies are composed of a few billion stars, while larger galaxies can contain hundreds of billions of stars. The Milky Way, according to the European Space Agency, has at least 14 satellite dwarf galaxies. They do not feature spiral arms or bulges like larger galaxies.
“The Milky Way, like all large galaxies, is believed to have formed through the build-up of smaller dwarf galaxies in the early years of the universe,” according to the ESO. “These small galaxies, if they have survived on their own up to the present day, now normally contain many extremely old stars.”
However, NGC 5291B, astronomers found, contains no old stars. Observations from the Very Large Telescope’s Multi Unit Spectroscopic Explorer revealed the galaxy boasted properties more in line with new star formation. Scientists theorize the unusual characteristics may result from massive gas collisions.
“This makes it a unique system in our local universe and an important laboratory for the study of early gas-rich galaxies, which are normally much too distant to be observed in detail by current telescopes,” according to the ESO.
NGC 5291 is located 200 million light-years away in the Centaurus constellation.
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