Eight more galaxies found orbiting the Milky Way

Seventeen dwarf galaxies (some marked above with red dots) have been found around the Milky Way this year, including eight recently announced. These satellites are often too faint for images, so astronomers use maps of star density (inset) instead.

Dark Energy Survey collaboration

By Christopher Crockett

August 19, 2015 at 8:25 am

The neighborhood around our galaxy is getting a little crowded. Eight more satellite galaxies have been found buzzing around the Milky Way, researchers report online August 16 at arXiv.org. This brings the number of known Milky Way cohorts to nearly 50, when combined with nine other satellites discovered earlier this year.

Our galactic groupies are pint-sized — the smallest contains just 161 stars — and sit between about 80,000 and 700,000 light-years from Earth. These teeny tagalongs are almost entirely made of dark matter, which makes them excellent laboratories for studying the elusive substance that holds galaxies together.

Editor’s note: This post was updated on September 1, 2015, to correct the number of stars in the smallest galaxy.