A new dwarf galaxy has been spotted in our galactic backyard. A Russia-led research team found Kks3 using the Hubble Space Telescope’s Advanced Camera for Surveys (ACS).
Located 7 million light years away, Kks3 is tiny in comparison to our own galaxy. It’s mass is just one ten-thousandth the size of the Milky Way and lacks features such as spiral arms. Kks3 also lacks the raw materials to form new stars.
Why? According to Astrobiology Magazine, the gas and dust needed to aid new star formation is often siphoned away by nearby massive galaxies such as our own or Andromeda. Most dwarf galaxies are located near much bigger galaxies.
But, Kks3 wasn’t discovered near a much larger companion galaxy. So, how did it lose all of its dust and gas needed for creating new stars? One possibility is that an early burst of star formation could have exhausted all of the galaxies’ materials. Scientists aren’t completely sure though.
The discovery of Kks3 raises another question for astronomers. How many other dwarf galaxies lie within the Local Group, where dozens of galaxies including ours, are known to be located?
“Finding objects like Kks3 is painstaking work, even with observatories like the Hubble Space Telescope. But with persistence, we’re slowly building up a map of our local neighbourhood, which turns out to be less empty than we thought,” said Prof Dimitry Makarov of the Special Astrophysical Observatory in Russia.
“It may be that are a huge number of dwarf spheroidal galaxies out there, something that would have profound consequences for our ideas about the evolution of the cosmos.”
The hunt for more dwarf spheroidal galaxies, especially isolated ones such as Kks3, will continue. Newer telescopes such as the European Extremely Large Telescope and the James Webb Space Telescope should make Makarov and his team’s work a bit easier. But, those are still several years away.
Image credit: Dimitry Makarov