The Hubble team has released a close-up image of the dwarf irregular galaxy UGC 8091, which resembles a sparkling festive snow globe.
This Hubble image shows UGC 8091, a dwarf irregular galaxy some 7 million light-years away in the constellation of Virgo. The color image was made from separate exposures taken with Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3). Image credit: NASA / ESA / Hubble / Yumi Choi, NSF’s NOIRLab / Karoline Gilbert, STScI / Julianne Dalcanton, Center for Computational Astrophysics & Flatiron Institute, University of Washington.
UGC 8091 is located around 7 million light-years away from Earth in the constellation of Virgo.
Otherwise known as GR 8, DDO 155, LEDA 44491 or TC 257, this galaxy was discovered by astronomers at the Lick Observatory in the 1940-50s.
“Unlike other galaxies whose stars take a more orderly appearance, UGC 8091 is classified as an irregular galaxy,” Hubble astronomers said.
“It’s not hard to see why — the stars that make up this celestial gathering look more like a brightly shining tangle of string lights than a galaxy.”
“Some irregular galaxies are thought to have become tangled by tumultuous internal activity, while others are known to have formed by interactions with neighboring galaxies.”
“The result is a class of galaxies with a diverse array of sizes and shapes, including the diffuse scatter of stars that is this galaxy.”
Also classified as a dwarf irregular galaxy, UGC 8091 contains around one billion stars.
“That’s a huge number of lights, but not for a galaxy: our own Milky Way Galaxy is thought to encompass over 100 billion stars, and other galaxies can have trillions,” the astronomers said.
“Dwarf galaxies often orbit larger galaxies, and their low masses leave them vulnerable to being disturbed and consumed by their bigger neighbors, a process which produces twisted-up dwarf irregulars like UGC 8091.”
“This type of galaxy is thought to have similar characteristics to the enormously old and distant galaxies seen in deep-field images.”
“It’s hoped that investigating the composition of dwarf galaxies and their stars, particularly their low metallicity, will help to uncover the evolutionary links between these ancient galaxies and more modern galaxies like our own.”
To do this, the researchers have been carefully examining the many-colored stars of UGC 8091.
“Different features of the galaxy can be picked out by using filters to restrict the light entering Hubble’s instruments to very specific wavelength ranges,” they said.
“Those filtered images can then be recombined to make a full-color image — an astonishing twelve filters combine to produce this image, with light from the mid-ultraviolet right through to the red end of the visible spectrum contributing.”
“The blossoming patches of red represent light emitted by excited hydrogen molecules in hot, energetic stars that have formed in recent starbursts.”
“The other sparkles on show in this image are a mix of older stars.”
