Using the Hubble Space Telescope, astronomers have discovered a dwarf galaxy in a globular cluster which is only 30 million light-years away.
The team used the NASA/ESA (European Space Agency) telescope to study white dwarf stars within the globular cluster NGC 6752.
The aim of their observations was to use these stars to measure the age of the globular cluster, but in the process they made an unexpected discovery, according to the study published in the journal Monthly Notices of the Royal Astronomical Society: Letters.
In the outer fringes of the area observed with Hubble’s camera, a compact collection of stars was visible.
After a careful analysis of their brightnesses and temperatures, the astronomers concluded that these stars did not belong to the cluster — which is part of the Milky Way — but rather they are millions of light-years more distant.
The newly discovered cosmic neighbour, nicknamed Bedin 1 by the astronomers, is a modestly sized, elongated galaxy, the study said.
It measures only around 3, 000 light-years at its greatest extent — a fraction of the size of the Milky Way. Not only is it tiny, but it is also incredibly faint.
These properties led astronomers to classify it as a dwarf spheroidal galaxy.
Dwarf spheroidal galaxies are defined by their small size, low-luminosity, lack of dust and old stellar populations.
The international team of astronomers that carried out this study consists of researchers from University of California Los Angeles, University of Bonn in Germany and Universite de Montreal in Canada, among others.