A team of Australian researchers has revealed a hidden woman underneath a 19th century painting by the famous French impressionist Edgar Degas using x-ray fluorescence. Although the researchers cannot identify who the hidden figure in Degas’s Portrait of a Woman is, they suggest that she was Emma Dobigny, a French model who Degas had affection for.

For many years, researchers have known that Portrait of a Woman, which Edgar Degas painted between 1876 and 1880, has a concealed figure but they could not properly assess it until now. Researchers from the Australian Synchrotron used a non-invasive x-ray fluorescent microscopy to scan the painting, revealing the woman in clear detail.

According to Daryl Howard, co-author of the study now published in the journal Scientific Reports, the hidden woman could be Dobigny because other portraits of the French model look like it. However, the team was not expecting to see so much detail using the technique.

Edgar Degas

Hidden figure under Portrait of a Woman. Credit: National Gallery of Victoria

“The X-ray fluorescence technique used at the Australian Synchrotron has the potential to reveal metal distributions in the pigments of underlying brushstrokes, providing critical information about the painting,” Howard told Smithsonian.com. “This detector allows us to scan large areas of an object such as a painting in a short amount of time in a non-invasive manner.”

The study could improve the way art is studied and interpreted, says Howard. The technique is an effective tool that can help conservators from around the world.

Using the x-ray process can also shed light into how an artist’s painting technique has changed over time as well as the method used to preserve painting. This information could also be used for scholarly purposes.

Howard adds that doing such task before was difficult. Now, you do not have to be an expert to use it. This means that it could take off and more people are going to use it soon to analyze other paintings.