On February 4, 2019, the Hubble Space Telescope discovered a small and isolated dwarf galaxy just a meniscal 30 million light-years away from our own Milky Way. The astronomers said the discovery was entirely by accident, and that this could provide a lot of new insights into understanding how our own galaxy was formed as well as learning about how and potentially what causes a dwarf galaxy. The dwarf galaxy is named the Bedin 1 Galaxy.
Luigi Bedin and his colleagues were using Hubble to study a globular star cluster called NGC 6752. Globular clusters are tightly packed crowds of ancient stars. when the scientist looked at the images Hubble sent back; they noticed a small galaxy hiding behind the cluster’s brighter stars in their image, which they decided to call the galaxy, Bedin 1 by its discoverer, Luigi Bedin. Bedin is distinct in its isolation, which is a description of the galaxy discovered and not the social habits of the scientist.
There’s a small chance that this swirl of stars may be connected to a more massive galaxy, but the two are farther apart than would be typical, and it’s not clear they have ever interacted before. Particularly what makes Bedin 1 so interesting for astronomers – first, most dwarf galaxies are found huddled up closer to a more massive galaxy; second, Bedin 1 shows little sign of past interactions with any galactic neighbors.
These dwarf galaxies are actually a common occurrence in the universe, and most of them ride the gravity waves of massive galaxies. Because normal galaxies, such as our the Milky Way, are hundreds or sometimes even thousands of times more massive than these smaller dwarf galaxies are at the gravitational mercy of their larger brethren. Astronomers have often noted evidence of smaller galaxies being pulled apart or consumed by larger ones. And all this activity can often mean complex histories of star formations. However as old stars get ripped away and gases get pushed around, sparking new generations of stars.
When galaxies make stars, they tend to do so in batches that include all types at once: giant stars that burn hot but die quickly, or small stars that live longer than the universe’s lifespan so far. Nearly all the stars astronomers measured in Bedin 1 are small and old, implying the dwarf galaxy made all its stars in a single burst of activity some 10 billion years ago. Bedin 1 has sat quietly ever since, letting its massive stars burn out and die. Making no new stars to replace them, undisturbed by the cosmic chaotic shuffle around it.