When the Hubble Space Telescope photographed the globular star cluster NGC 6752 (located 13,000 light-years away in our Milky Way’s halo), the image revealed a never-before-seen dwarf galaxy cataloged as Bedin 1 located far behind the cluster’s crowded stellar population. The galaxy is only 30 million light-years away but had not been noticed before. It’s classified as a dwarf spheroidal galaxy because it measures only around 3,000 light-years at its greatest extent. Because it’s so small, it’s roughly a thousand times dimmer than the Milky Way.
Because it’s very old, 13 billion years, and relatively isolated, it’s seen hardly any interaction with other galaxies It’s the astronomical equivalent of a living fossil from the early universe.
This composite image above shows the location of Bedin 1 behind the globular cluster NGC 6752. The lower image of the complete cluster is a ground-based observation from the Digitized Sky Survey 2. The upper right image shows the full field of view of the Hubble Space Telescope. The upper left image highlights the region containing the galaxy Bedin 1.
Image Credits: NASA / ESA / DSS / STScI