But, having studied the brightness and temperature of the observed stars, the experts understand that they were not a constellation at all, but were approximately 2300 times farther apart. The researchers published their findings in the journal Monthly Notices of the Royal Astronomical Society: Letters. The final view, from the NASA/ESA Hubble Space Telescope, shows the bright stars of the cluster, as well as a collection of faint stars; these faint stars are actually part of a background galaxy, which was discovered accidentally by astronomers studying the cluster itself.
The scientists that made this discovery are now calling the galaxy Bedin 1, after the lead discoverer, Luigi Bedin. It measures only 3000 light years - a fraction of the size of the milky way. Needless to say, Bedin 1 is also quite faint, which led the astronomers to classify it as a dwarf spheroidal galaxy. In a celestial game of "Where's Waldo?", Hubble's sharp vision uncovered a never-before-seen dwarf galaxy located far behind the cluster's crowded stellar population. Within the Local Group of Galaxies, there are about 36 of the dwarf spheroidal type, and among them, 22 are satellite galaxies of the Milky Way.
So with Bedin 1 found, it's one down, 1,999,999,999,999 to go. It lies about 30 million light-years from the Milky Way and 2 million light-years from the nearest plausible large galaxy host, NGC 6744. It's thought that Bedin 1 is the most isolated dwarf galaxy known to exist.
It's estimated to be roughly 13 billion years old based on the properties of its stars, meaning it is nearly as old as the universe itself. Because of its isolation - which resulted in hardly any interaction with other galaxies - and its age, Bedin 1 is the astronomical equivalent of a living fossil from the early Universe.
"The discovery of Bedin 1 was a truly serendipitous find", the ESA said.
The astronomers also note that a survey planned for the upcoming Wide Field Infrared Survey Telescope (WFIRST, planned to launch in the mid-2020's) may find more of these small, hermit-like galaxies.