In a new image from Gemini Observatory, we stare into the heart of a group of galaxies situated in the Andromeda constellation. Called VV166, the group is situated around 300 million light-years from Earth. Clearly, they are extraordinarily beautiful, but from a scientific perspective, the group is most known for exhibiting a wide range of features, each galaxy coming in a different form.
In fact, astronomers use them to study “herd dynamics’ in galaxy form, since galaxy groups share a common center of mass and they travel through space together, often gravitationally interacting in the process. To some, they pose an intriguing question: do galaxies in galaxy groups also share a common origin, or is there more to it than that?
It’s unlikely that VV166 will definitively answer that question for us, but perhaps they can still shed light on other astronomical phenomena. If not, they are still lovely to look at.
Individually, we have NGC 70: the blue spiral galaxy situated top and center. It’s as large as it is beautiful, spanning approximately 180,000 light-years across (making it about 80% larger than the Milky Way), Within its boundaries, lots of star forming is taking place, which is where the blue hue comes from.
Next, we have the central galaxy, NGC 68 (pictured below NGC 70). Unlike NGC 70, it’s an elliptical galaxy with remarkably less star formation activity brewing (one of the defining features of an elliptical galaxy, which tend to be older, and more evolved). Additionally, NGG 68 is around 20 million light-years closer to us; some astronomers believe it might not be a member of VV166 at all, but a chance alignment.
Then, we have NGC 71: a lenticular galaxy with no clearly defining features. It may, however, bear signs of a gravitational perturbation between it and NGC 68, maybe even another neighbor too. Evidence comes in the form of distorted arms.
Finally, we come to NGC 72: a barred spiral galaxy with a prominent central bar, expansive dusty spiral arms, and a ring of newly-formed stars.