For more than a century, Vincent van Gogh’s “The Starry Night” was viewed as a product of imagination, memory and earlier drawings. Scientists in South Korea now say the 1889 painting may preserve the structure of a real night sky.

The study, published Thursday in Scientific Reports, links the painted skyscape to the celestial arrangement visible before dawn on July 22, 1889. The canvas shows bright stars, a luminous crescent moon and swirling colors above a cypress tree and village.

Researchers from space science company SLLAB and Kyung Hee University in Seoul used another van Gogh drawing believed to depict the same landscape. They identified a hilly site southwest of the asylum near Saint Rémy de Provence, France.

Van Gogh created the oil painting during a 12 month stay at the asylum. A simulation of the sky above the identified site showed the moon high in the upper right and Venus near the lower left during the early hours of July 22.

Between them was the Hyades cluster, which contains hundreds of stars in the Taurus constellation. Five bright stars in the constellation can be seen without a telescope, while the cluster forms a bright “V” shape.

The painting places the moon in its upper right corner, diagonally above Venus near the center left. Other painted stars appear to the left of the moon, creating the central arrangement examined by the researchers.

“A painter does not draw stars at their true size or orientation. A star cluster on the canvas may be larger or smaller than in reality, and slightly tilted,” lead author Elijah Jeong-hyun Kim, an astronomer, engineer and SLLAB CEO, told CNN.

The team used Procrustes shape analysis, which removes differences in position, scale and rotation before comparing arrangements. That method allowed the researchers to match five stars in the painting with the shape of the Hyades cluster on the proposed date.

“The relative positions of the stars preserve the skeleton of the Hyades,” the researchers concluded. They said the result indicates the painting transferred an observed celestial arrangement onto the canvas through stylistic amplification rather than inventing an entirely absent sky.

The same technique connected van Gogh’s 1888 painting “Café Terrace at Night” with the Summer Triangle star pattern. However, the Museum of Modern Art in New York, where “The Starry Night” is housed, dates the painting to mid June 1889.

That date is based on a letter van Gogh wrote to his brother Theo around June 18 mentioning “a new study of a starry sky.” The study says the moon around that time appeared almost full, unlike the waning crescent in the painting.

“Also, around June 19 is close to the summer solstice, when no impressive stars rise in the pre-dawn sky,” Kim told CNN. “Around July 22, by contrast, the Hyades rose in the east together with Venus, and the moon’s shape was close to the crescent in the painting.”

An earlier examination of the canvas found that van Gogh left spaces for stars unpainted before filling them after completing the blue sky. Researchers said this suggests the pattern was planned, but questions remain about a seizure van Gogh may have experienced in mid July.

The team reviewed original French and Dutch letters along with contemporary weather records. It concluded the seizure could have occurred in late July and may have lasted only a day or two, potentially leaving time for van Gogh to observe the sky.

Yongxiang Huang of Xiamen University called the framework engaging but warned that painted alignments require caution. Ulrike Kuchner, an astronomer and art science researcher, described the study as “exciting detective work,” while noting that artistic license could explain the moon’s shape.

The study was limited by 19th century weather records and cannot establish when van Gogh started or reworked the painting. Researchers assume he combined observations from several nights, with Kim proposing that van Gogh may have conceived the work in June and completed it after July 22.