Galaxies are large clusters of stars, gas and dust held together by gravitational forces and orbiting a central point. A dwarf galaxy is a much smaller group which is, apparently, devoid of gas and dust particles.

In the case of Kks3, a ‘dwarf spheroidal’ or dSph galaxy recently discovered by Prof Igor Karachentsev of the Special Astrophysical Observatory in Karachai-Cherkessia it is only ten-thousandth of the mass of the Milky Way. The dwarf galaxy is part of ‘local group’ that our galaxy belongs to. That local group is a collection of 50 galaxies of varying sizes including large galaxies like Andromeda and much smaller groups.

As reported in the Monthly Notices of the Royal Astronomical Society, Kks3 is located 7 million light years away in the southern sky in the direction of the constellation of Hydrus. The dwarf galaxy contains no dust or gas and so cannot form new stars. The dust and gas appears to have been stripped out by the nearby Andromeda galaxy. The majority of dSph objects are found near much bigger companions, like the leftovers of galactic formation.

It is thought that objects within the dwarf galaxy formed in a different way than objects in our own galaxy. One possibility is that they formed from an early star burst that used up the gas resources of the galaxy. Astronomers are particularly interested in groups dSph objects because understanding them would help paint a better picture of galaxy formation in general.

Karachentsev’s team found the galaxy using the Hubble Space Telescope Advanced Camera for Surveys (ACS) in August of this year. It is the same team the found the only other isolated dwarf spheroidal in the local group, KKR 25, in 1999. Objects like these are made more difficult to find because of the lack of nebulae and clouds of raw materials. Researchers are forced to locate them by tracking individual stars.

“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. 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,” said team member Professor Dimitry Makarov in a statement.

The task of finding dSph galaxies for this team and others will be made easier with the next generation of telescopes.

The James Webb Space Telescope is a collaborative effort between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). The large infrared telescope has a 6.5-meter primary mirror and a variety of infrared instruments. The Webb telescope is designed to study, among other things, the assembly of planetary systems, the birth of stars and the assembly of Galaxies. The launch for the highly anticipated telescope is scheduled for 2018. NASA’s website features web cams that allow visitors to watch the James Web Telescope being constructed.

The European Extremely Large Telescope (EELT) is a highly sophisticated instrument being constructed in the Atacama Desert of northern Chile. The one billion euro telescope is expected to be completed by 2022. Like the Webb, the EELT will study the formation of galaxies, stars and planets as well as assisting in the search for exoplanets.