Researchers from Texas State University have used forensic astronomy to uncover new details about Claude Monet's Étretat: Sunset — a stunning seascape that the impressionist master painted during a trip to the Normandy coast in 1883. Their findings, published in the February 2014 issue of the magazine Sky & Telescope, reveal the exact spot and time at which Monet painted the work, based on extensive fieldwork and astronomical data.

Led by astrophysicist Donald Olson, the team traveled to the cliffs of Normandy in 2012, where they used postcard-size replicas of Monet's works to identify the precise vantage point from which he painted Étretat: Sunset. Once they identified the location, they used planetary software to determine what a 19th century sky would have looked like, focusing on the position of the moon and sun.

"separating the real from the unreal."

Monet created a series of paintings during his three-week winter trip to the region, though Sunset is the only one that includes the low-setting sun, depicted to the right of a seaside cliff and needle-shaped rock formation. Olson and his team visited the area during the summer, so the sun wasn't in the same position, but the crescent moon and star fields allowed them to determine the path along which the sun would've set. Based on their calculations, they concluded that Monet must have painted the work between February 3rd and 7th. After studying the letters Monet wrote during that time, as well as historical weather and tidal data, they narrowed the precise date to February 5th, 1883 at 4:53 PM local time.

Olson has spent his career doing similar analysis, covering paintings by Edvard Munch and Van Gogh, as well as works by Shakespeare and Walt Whitman. Reaction from art historians has been mixed over the years, with some questioning the merit of Olson's work, but the astrophysicist says his analysis doesn't diminish

"You can't ruin a painting's mystique through technical analysis," Olson said in a 2009 interview with Smithsonian Magazine. "It still has the same emotional impact. We are just separating the real from the unreal."