A galaxy residing near our own local group of galaxies, called Kks3, has been discovered by astronomers. This rare family of stars could help astronomers learn more about the Universe at large.
The Hubble Space Telescope was used to find the previously-unknown family of stars, just under 7 million light years away from Earth.
The galaxy Kks3, roughly 10,000 times lighter than the Milky Way, is seen in the southern constellation of Hydrus. It is only the second-known dwarf spheroidal galaxy in the local group, a collection of 54 groups of stars which include our own galaxy.
"Finding objects like Kks3 is painstaking work, even with observatories like the Hubble Space Telescope... 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," Dimitry Makarov, from the Special Astrophysical Observatory, said.
Dwarf spheroidal (dSph) galaxies do not exhibit distinct features, like the spiral arms of the Andromeda Galaxy, another member of the local group. They also lack much of the material needed to produce new stars. Therefore, most of the stars in dwarf spheroidal galaxies are old, and the bodies are not producing new stellar families.
Much of the material which would have gone into building new stars in these galaxies is stripped away by the gravitational pull of larger companions, like Andromeda. Because of this, astronomers usually need to find dSph objects by locating individual stars, rather than clouds of hydrogen gas. This makes it challenging for observatories, including Hubble, to find the objects past our local group of galaxies.
Only one other dSph object, KKR 25, has been discovered in the local group, in 1999, by the same Russian and American team that found Kks3.
The James Webb Telescope, designed as a successor to the Hubble Space Telescope, is scheduled for launch in 2018, but delays could push that mission back. That observatory, together with observations made from the ground using the future European Extremely Large Telescope, could help astronomers find additional dwarf spheroidal galaxies like Kks3.
Astronomers who helped discover Kks3 will continue to search for other dwarf spheroidal galaxies, in an effort to understand their formation, composition, and evolution. Investigation of dSph objects could also assist astronomers in uncovering information about the evolution of other types of galaxies.
Discovery of Kks3 was detailed in an article published in the journal Monthly Notices of the Royal Astronomical Society.