Hubble Astronomers Accidentally Discover Tiny, Isolated Dwarf Galaxy

The Hubble Space Telescope has been collecting information about our solar system (and beyond) for decades now, helping scientists to directly observe planets, stars, and other phenomenon in the universe. Sometimes, though, the telescope helps us to make accidental discoveries too:  as in the new galaxy they found this week.

Analyzing data from the Hubble Space Telescope, researchers were studying white dwarf stars in the globular cluster NGC 6752. This is a spherical star group that orbits the core of our Milky Way galaxy. The researchers had been hoping to learn about the age of this particular globular cluster by simply studying the stars.  During the process, however, the team actually found another faint cluster of stars towards the right edge of the Advanced Camera for Surveys viewing field.  Upon further inspection of this cluster’s brightness and temperatures, they realized these were not actually part of the globular cluster at all.  Instead, theses stars are much further away. 

As a matter of fact, this newly discovered cluster of stars is several million light years away. More importantly, the researchers identified that these stars are part of a small galaxy with a 3000 light year diameter.  In terms of galaxies, that is pretty small, but its faintness means that we probably would have never discovered if scientists were not already looking directly at that part of the galaxy in close detail.  

At the end of the day, the, scientists have classified this discovery as a dwarf spheroidal galaxy and named it Bedin 1. Its namesake is Luigi Bedin, who is an astronomer with the Italian National Institute for Astrophysics and, more importantly, he was the leader of the team who made this remarkable discovery. 

This galaxy is unusual, though, because it is isolated from other galaxies.  The nearest large galaxy is NGC 6744, which about 2 million light years from Bedin 1. And Bedin 1 is about 30 million light years away from our Milky Way.  

In the official video, Hubble officials say, “The Whirlpool Galaxy is perhaps the most striking example of a spiral galaxy. Different wavelength observations reveal different structures in the galaxy. In three dimensions, the galaxy’s spiral arms whirl through a pancake-shaped disk.”