Found! Seven Dwarfs Surround The ‘Pinwheel Galaxy’ Field Of View

Using a unique type of telescope that includes long-range lenses, astronomers at Yale University have found seven dwarf galaxies surrounding the well-known Pinwheel Galaxy, M101.

It’s unclear if the septuplets are actually orbiting the pinwheel, or just happen to be in the same field of view. But astronomers at Yale say that this shows the so-called Dragonfly Telephoto Array is working well, and they are planning follow-up observations to see what else they can find.

“The previously unseen galaxies may yield important insights into dark matter and galaxy evolution, while possibly signaling the discovery of a new class of objects in space,” Yale University stated in a release.

The galaxies escaped detection before because their light is so diffuse, but this is what the telescope is designed to pick up. The telescope is constructed of eight telephoto lenses (similar to what you would use to photograph a sporting event) that include “special coating” to stop any light from scattering inside. The telescope is called “Dragonfly” because like an insect, it has multiple eyes for looking at things.

The Dragonfly Telephoto Array, a unique Yale University telescope used to look for diffuse light in galaxies. Credit: Yale University
The Dragonfly Telephoto Array, a unique Yale University telescope used to look for diffuse light in galaxies. Credit: Yale University

Follow-up observations will come with the Hubble Space Telescope. If it turns out that these galaxies are not bound to M101, the results will be equally interesting to astronomers.

“There are predictions from galaxy formation theory about the need for a population of very diffuse, isolated galaxies in the universe,” stated Allison Merritt, a Yale graduate student who led the research.

“It may be that these seven galaxies are the tip of the iceberg, and there are thousands of them in the sky that we haven’t detected yet.”

The research was published in Astrophysical Journal Letters and is also available in preprint version on Arxiv.

Source: Yale University

A Cotton Candy Pinwheel Galaxy


Just in time for summer, this image of the Pinwheel Galaxy (M101) looks as pretty as a child’s toy and as delectable as cotton candy. This beautiful image combines data in the infrared, visible, ultraviolet and X-rays from four of NASA’s space-based telescopes. It’s like seeing with a regular camera, an ultraviolet camera, night-vision goggles and X-ray vision, all at the same time.

But within this multi-spectral view, you can see both young and old stars distributed along M101’s tightly-wound spiral arms. Composite images like this allow astronomers to see how features in one part of the spectrum match up with those seen in other parts.

The Pinwheel Galaxy is in the constellation of Ursa Major (also known as the Big Dipper). It is about 70 percent larger than our own Milky Way Galaxy, with a diameter of about 170,000 light years, and sits at a distance of 21 million light years from Earth. This means that the light we’re seeing in this image left the Pinwheel Galaxy about 21 million years ago – many millions of years before humans ever walked the Earth.