Astronomer Calculates When van Gogh Painted This

One of my favorite paintings is Starry Night by Vincent van Gogh — for obvious astronomical reasons. But another favorite of van Gogh’s works is Lane of Poplars at Sunset. This painting depicts the setting Sun perfectly aligned with a long lane of trees, casting long shadows.

The geometry of the Earth and Sun means that this scene had to be painted on one specific day of the year when the alignment would be possible. An astronomer has now used 19th-century maps to discover where the lane was, and then used astronomical calculations to determine which date the Sun would be in the exact position as the painting. His result? The painting depicts a stretch of road known as Weverstraat in the Dutch town of Nuenen, on November 13 or 14, 1884.

Professor Donald Olson is an astronomer and physics professor emeritus at Texas State University (TSU). He is no stranger to studying van Gogh paintings, as in the past he has uncovered clues to help date three other of the noted painter’s works: Moonrise (July 13, 1889), Road with Cypress and Star (May 1890) and White House at Night (June 1890).

Van Gogh produced more than 2,000 paintings, drawings, and sketches in his lifetime, and many include scenery from The Netherlands, the Dutch master’s home. Olson was originally inspired to determine the date of Lane of Poplars at Sunset because the scene shows something similar to what happens twice a year for New York City’s “Manhattanhenge,” where the setting sun aligns with Manhattan’s east–west streets on dates near May 29 and July 12.  

The first thing Olson wanted to figure out was where the lane might be.

“If we could identify the lane on 19th-century maps, then we’d be able to establish the compass direction of the road appearing in the artworks,” Olson explained in a news release from TSU. “Next, we could use astronomical calculations to determine the date when the disk of the setting sun aligned as van Gogh portrayed it.”

Olson called in assistance from Louis Verbraak and Ferry Zijp, members of the Eindhoven Weather and Astronomy Club in the Netherlands. After an exhaustive search of maps and correlating historic and recent imagery, the team narrowed it down to three possible streets. Further investigations led them to determine that Weverstraat in Nuenen must be the street, as it contained a long straightaway of 1,200 feet, or 365 meters, more than long enough for the scene painted by van Gogh.

As for determining the date, Olson and team relied on historical information. All of van Gogh’s paintings assigned catalog numbers, in order by dates determined by art historians. Lane of Poplars at Sunset is assigned as F123. The previous painting in the catalog, F122, is called Lane of Poplars in the Autumn, which shows the same scenes with vivid fall colors, while the leaves are almost completely gone from the trees in the sunset depiction. That means the painting had to be done in late fall.

Art historians have also long depended on van Gogh’s many letters to his brother Theo to help date most of the artist’s work. A total of three letters, written by Vincent during late October and early November of 1884, describe the lovely autumn weather he was experiencing. One letter, dated on or about Oct. 25, 1884, includes a description that matches Lane of Poplars in the Autumn:

“The last thing that I made is a rather large study of a lane of poplars with the yellow autumn leaves, where the Sun makes glittering patches here and there on the fallen leaves on the ground, alternating with the long shadows cast by the trunks. At the end of the road is a peasant cottage, and above it the blue sky between the autumn leaves.”

A subsequent letter dated on or about Nov. 14, 1884, van Gogh indicated that freezing weather forced him to abandon painting outdoors for the rest of the season. Additional letters helped establish a time frame between Nov. 5-Nov. 14 for van Gogh to have painted Lane of Poplars at Sunset. Within this range of dates, planetarium software shows that the sun set in the southwest, in the range of azimuths, or compass direction of a celestial object, between 240° and 244°.

Then using astronomical calculations, Olson and team determined the setting sun would’ve been visible setting over Weverstraat on Nov. 13 or 14, 1884. Historical weather records indicate these dates fall within a five-day span where the area experienced unseasonably clear weather.

Olson said that because van Gogh rarely painted from memory and preferred to have his subject in front of him, Nov. 13 or 14, 1884, are the only possible dates for the creation of Lane of Poplars at Sunset.

“Today, we can still gaze down the same stretch of road where van Gogh walked on a chilly autumn afternoon and ponder how the artist, in his native Netherlands, was already interested in portraying sky phenomena, four years before he began to create his famous starry nights in the south of France,” Olson said.

Read more details about the search at TSU.

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