Amateur astronomer spots dwarf galaxy that computers missed

By Georgina Torbet February 12, 2023

As machine learning approaches get more and more sophisticated, they are increasingly used in astronomy for difficult tasks like spotting dim and distant galaxy clusters. It can be tremendously helpful to have computers search through astronomical data to look for particular objects as they can process a huge amount of data — however, there are some judgments that still require the human touch.

This week’s image from the Hubble Space Telescope shows an object that was spotted by a human even after it had been missed by a computer algorithm. The dwarf galaxy Donatiello II is very faint and hard to pick out from the background behind it, but an amateur astronomer was able to point it out.

Right in the middle of this image taken with the NASA/ESA Hubble Space Telescope, nestled among a smattering of distant stars and even more distant galaxies, lies the newly discovered dwarf galaxy known as Donatiello II. If you can’t quite discern Donatiello II’s clump of faint stars in this image, then you are in good company. Donatiello II is one of three newly discovered galaxies. All three were missed by an algorithm designed to search astronomical data for potential galaxy candidates. Even the best algorithms have their limitations when it comes to distinguishing very faint galaxies from individual stars and background noise. In such challenging situations, identification must be done the old-fashioned way – by a dedicated human trawling through the data themselves. — Right in the middle of this image, nestled among a smattering of distant stars and even more distant galaxies, lies the newly discovered dwarf galaxy known as Donatiello II. ESA/Hubble & NASA, B. Mutlu-Pakdil; Acknowledgment: G. Donatiello

“Even the best algorithms have their limitations when it comes to distinguishing very faint galaxies from individual stars and background noise,” Hubble scientists write. “In such challenging situations, identification must be done the old-fashioned way – by a dedicated human trawling through the data themselves.”

The dwarf galaxy is located in the center of this image and was identified by Giuseppe Donatiello from data collected during the Dark Energy Survey. Along with two other similar dwarf galaxies named Donatiello III and IV, it orbits the Sculptor Galaxy. Once Donatiello spotted the trio in the Dark Energy Survey data, researchers used Hubble to confirm the discovery and take this image.

The Dark Energy Survey was a project that surveyed the sky from 2013 to 2019, looking at objects like galaxy clusters to understand more about dark energy. Though the survey is now complete, the data collected from the first three years of observations was released to the public in 2021 and is still leading to discoveries like this trio of dwarf galaxies.

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Georgina Torbet

Space Writer

Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…

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