The Andromeda and Triangulum galaxies, neighbors to the Milky Way, are constructed of an immense number of stars. But a new study, led by a West Virginia University graduate student, has revealed a never-before-seen cluster of gas clouds between the galaxies that could potentially fuel the formation of more stars.

The study is in this week’s issue of Nature, a weekly journal that highlights original and groundbreaking research in science.

Lead author Spencer Wolfe, a graduate student in the WVU Department of Physics, and assistant physics professor Daniel (D.J.) Pisano worked with researchers from Case Western Reserve University, the University of Maryland and the National Radio Astronomy Observatory.

The astronomers detected the clouds using the National Science Foundation’s Robert C. Byrd Green Bank Telescope at the NRAO site in Green Bank, W.Va.

Although previous observations of the Local Group, a galaxy group that includes the Milky Way, have indicated the possible presence of diffuse hydrogen gas between its members, this is the first time there has been such a detailed view.

“The question we’re trying to answer is in what way is the Local Group and its members evolving,” Wolfe said. “A lot of people tend to forget that when they see pictures of the Milky Way that we’re embedded in it. If it’s evolving, we’re going to evolve with it so understanding the details of how galaxies like the Milky Way can acquire new gas and keep forming stars is important.”

The study would not be possible without the unique capabilities of the Green Bank Telescope.”


Observations completed by the group have shown that portions of the gas are clumped together mimicking dwarf galaxies. Dwarf galaxies, are relatively small collections of stars bound together by gravity. They can contain anywhere from a few thousand to a few million stars. The telescope also was able to track the motion of these newly discovered clouds.

“The study would not be possible without the unique capabilities of the Green Bank Telescope,” Pisano said. “Its combination of sensitivity, resolution and its unique optical design were all critical for this study. There are no other telescopes currently operating or planned that will be as capable of doing this type of work as the GBT.”

Click here to view an animation by Bill Saxton/NRAO showing the discovery at the Green Bank Telescope.

Through their observations, the astronomers suggested the clouds represent a previously unrecognized source of hydrogen gas that could lead to future generations of star formation.

“It is a remarkable thing that there are still new things to discover in the back yard of our own galactic neighborhood,” said Stacy McGaugh, a professor of astronomy at Case Western Reserve University and co-author of the study.

“I’m fond of saying it is a big universe with lots left to discover; apparently that’s still true of our own ‘little’ corner of the universe.”

Read the full study in Nature:

For more information, contact D.J. Pisano, at 304-293-4886 or



CONTACT: Devon Copeland; Eberly College of Arts & Sciences

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