The Russian researchers from the Special Astrophysical Observatory in Karachai-Cherkessia, Russia have located an unknown dwarf galaxy named KKs3 about 7 million light years away from us located in the southern constellation of Hydrus. These researchers were working in tandem with Astronomers using Hubble Space Telescope’s advanced camera system and have collaboratively identified a new dwarf galaxy.
This discovery is quite unprecedented as KKs3 is well inside the well mapped “Local Group” of 50 known galaxies where the much famous Andromeda and our very own Milky Way reside. As a matter of fact, this finding has led astronomers to wonder that how many other close by dwarf galaxies have gone undiscovered.
This dwarf spheroidal galaxy accounts to just one by ten-thousandth of our Milky Way and also does not have spiral arms that many of the viewers might expect.
The Dwarf galaxies are fascinating objects as they don’t have the resources in terms of gas and dust required to create new generations of stars. But still, dwarf galaxies are very ancient and the observation of their stars is closely related to a cosmic archeological dig. Since they are quite old, their stars are also very dim making these dwarf galaxies very difficult to detect.
These dwarf galaxies normally orbit their big brothers like the Milky Way and Andromeda and are known to have several satellite dwarf galaxies and their star forming gases are thought to have been stolen by their more massive galactic neighbors. There are also possibilities that larger galaxies eat up these dwarfs during their formation. But KKs3 is not in any close proximity to another galaxy; it is completely isolated and joins a very exclusive club of only two galaxies. The other isolated dSph galaxy being the KKR 25 was found in 1999 and is also located in the same Local Group.
These isolated dSph galaxies were formed differently than their larger counterparts. Isolated dSphs are not affected by the gravitational forces of their neighbors, so they are likely to hold onto almost all of their star-forming gases but they consumed all of it in an early burst of star formation during the early days of the universe. An absence of interstellar gas indicates that astronomers have to scan intergalactic space very carefully so they don’t miss the faint stars of dSph galaxies. And that is why no dSphs have been found by Hubble out of the Local Group.