They identified 247,000 unknown galaxies thanks to the contribution of amateur astronomers

In the effort to galaxy mapping unprecedented, 10,000 amateur astronomers around the world have succeeded in identifying 247,000 galaxies in the search for distant objects that inhabit our Universe.

With the lens set in a Innovative project discover the enigmatic properties of dark energya team of scientists from the McDonald Observatory of University of Texas, in Austin, USA, recruits helpers for the intense search for galaxies and other space bodies. This pioneering effort could potentially shed light on one of the greatest mysteries of our universe: dark matter.

Known as HETDEX, or Hobby-Eberly Telescope Dark Energy Experiment, the research project relies on volunteers participating online in a project called Dark Energy Explorers. There, participants can find out what it’s like to be an astronomer Using a smartphone or computer, unravel the mysteries of the universe while helping professional astronomers find distant galaxies and learning more about the mysterious force known as dark energy, which causes the rapid expansion of the universe.

Since the launch of Dark Energy Explorers in February 2021, more than 10,000 volunteers have identified approximately 240,000 galaxies. That’s about one-tenth the number of galaxies researchers hope to eventually find in their study of a patch of sky that includes most of the Big Dipper and is about the size of 2,000 full moons.

“That’s why we need more people,” said Karl Gebhardt, professor of astronomy at UT Austin and project scientist and principal investigator for HETDEX. “If we can reach 100,000 people as volunteers, which I think is doable worldwide, we’ll be there next year.”

Dark Energy Explorers uses the Zooniverse platform, the largest amateur science organization in the world. Users participate through website Zooniverse or the Zooniverse smartphone app (available for iOS there android). Participants can create a free account and then select Dark Energy Explorers from a list of projects.

After a short tutorial, volunteers look at astronomical images and decide whether the objects they see are galaxies or random noise, a distinction that even the most sophisticated software struggles to detect. Volunteers then swipe left or right to indicate whether an image shows a galaxy.

“It’s really exciting to see how enthusiastic the public is about classifying these galaxies,” said Lindsay House, the UT Austin graduate student leading the project. The goal is to build the largest 3D map of the cosmos, fully focused on the galaxies of the early universe to help reveal important clues about dark energy.

The massive research project is designed to reveal whether dark energy changes over time or is constant. It is believed that at least two-thirds of the universe is made up of dark energy, but scientists know little about this. Understanding how dark energy behaves is a crucial first step to discovering exactly what it is, but astronomers need a large sample of distant galaxies to study and observe dark energy in action. This is HETDEX: a massive survey of over a million distant galaxies using one of the world’s largest optical telescopes, the 11-meter Hobby-Eberly Telescope at the McDonald Observatory in the west from Texas.

These galaxies emit a characteristic wavelength of light (Lyman-alpha), signaling intense starmaking activity. For the first time, researchers have listed more than 51,863 high redshift Lyman-alpha emitter galaxies, 123,891 lower redshift star-forming galaxies, 5,274 low redshift non-emitting linear galaxies, and 4,976 active galactic nuclei, points luminous signaling the presence of black holes.

“This new catalog adds valuable data to finally answer the ‘million galaxy’ question, which the HETDEX collaboration will be working very hard on next year,” said one of the study’s co-authors, Karl Gebhardt.

Dark Energy Explorers volunteers review HETDEX images, helping to reduce the time astronomers spend on this task by 90%. This way, the pros can focus their energies on the tougher leaderboards. “We’ve tried writing computer code to do this and even used machine learning, but found that the human eye is vastly superior. At first we were skeptical, but were surprised at the accuracy” , said Gebhardt.

To identify the 247,000 galaxies so far, the volunteers needed 3.75 million observations. Many more swipes than galaxies are needed as each candidate galaxy is reviewed by around 15 people to help build consensus and increase accuracy.

Dark Energy Explorers was created by a team led by graduate student Lindsay House, HETDEX Principal Investigator Karl Gebhardt, HETDEX Data Scientist Erin Mentuch Cooper, Professor and Astronomy Education Expert Keely Finkelstein, Postdoctoral Researcher Chenxu Liu and graduate student Dr. Dustin Davis.

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