Étienne Léopold Trouvelot’s Stunning 19th-Century Astronomical Drawings of Celestial Objects and Phenomena
By Maria Popova
“I sometimes ask myself whether I would be studying galaxies if they were ugly,” pioneering astronomer Vera Rubin observed in reflecting on our ongoing quest to know the universe. Hardly anyone has championed the role of beauty as a catalyst for cosmic enchantment more powerfully than the French artist and astronomer Étienne Léopold Trouvelot (December 26, 1827–April 22, 1895).
Trouvelot published more than fifty scientific papers in his lifetime, but remains best known for his exquisite astronomical illustrations. He created more than seven thousand, among them some of the most beguiling contributions to our long history of visualizing the cosmos. Emma Converse — the remarkable forgotten woman who popularized astronomy a century before Carl Sagan — called Trouvelot “the prince of observers.” The aesthetic splendor and scientific rigor of his illustrations so impressed the director of the Harvard Observatory that Trouvelot was invited to join the observatory staff, which he did in 1872.
Determined to make astronomy more accessible and captivating to the public, he set about depicting “the celestial phenomena as they appear to a trained eye and to an experienced draughtsman.” Using the era’s “great modern telescopes, provided with the most delicate instrumental appliances,” he made astronomical observations and translated them into stunning art, most remarkable of which were his painstaking pastel drawings created over the course of two years in the early 1870s — a period when Eadweard Muybridge was pioneering another revolutionary union of art and science on the other side of the country.
The best of Trouvelot’s pastels were exhibited alongside Alexander Graham Bell’s telephone, Heinz Ketchup, the first commercially successful typewriter, and the torch-clutching right arm of the Statue of Liberty at the first World’s Fair in Philadelphia — the Centennial International Exhibition of 1876, celebrating the 100th anniversary of the Declaration of Independence.
Trouvelot writes in the introduction, penned in March of 1882:
During a study of the heavens, which has now been continued for more than fifteen years, I have made a large number of observations pertaining to physical astronomy, together with many original drawings representing the most interesting celestial objects and phenomena.
While my aim in this work has been to combine scrupulous fidelity and accuracy in the details, I have also endeavored to preserve the natural elegance and the delicate outlines peculiar to the objects depicted; but in this, only a little more than a suggestion is possible, since no human skill can reproduce upon paper the majestic beauty and radiance of the celestial objects.
Indeed, there is a largehearted and deeply humane aliveness to Trouvelot’s work. Bellowing from it is also a peculiar paean to how art, science, and technology shape one another. The instruments with which he made his observations ranged from 6 to 26 inches in aperture and the primary telescope he used was 26 inches long. For comparison, the Gran Telescopio Canarias — currently Earth’s largest telescope — has an aperture of 409 inches; the Hubble Space Telescope, which has furnished our most picturesque images of the cosmos, is 516 inches long.
It is through this lens of technology’s limitations that Trouvelot, writing at the dawn of astrophotography, makes a beautiful case for the irreplaceable rewards of the artistic human touch beyond the mechanical imaging of instruments:
Although photography renders valuable assistance to the astronomer in the case of the Sun and Moon … for other subjects, its products are in general so blurred and indistinct that no details of any great value can be secured. A well-trained eye alone is capable of seizing the delicate details of structure and of configuration of the heavenly bodies, which are liable to be affected, and even rendered invisible, by the slightest changes in our atmosphere.
Trouvelot used a meticulous technique to create his drawings: At the eyepiece of the telescope, he placed a gridded reticle etched in glass, so that the telescopic image would appear projected onto the reticle. He would then copy the projection onto a sheet of ruled paper gridded with corresponding squares, using that as the skeleton of the pastel drawing.
Unlike the rest of his illustrations, which depict objects and phenomena as they appear in a single moment in time, Trouvelot’s drawing of the November meteor shower is a progenitor of timelapse photography. It represents what he called “an ideal view.” Rather than capturing the sky at any one moment, the drawing composites multiple shooting stars out of the three thousand observed between midnight and 5 A.M. that night. Although most of the meteors depicted did not cross the sky at the same time in actuality, Trouvelot preserved the actual color and trajectory of each in the idealized composite drawing.
Beyond the abiding aesthetic pleasures of his work, Trouvelot made substantive contributions to science. He was especially enchanted by the Sun and, during his time at the Harvard Observatory, discovered what he called “veiled spots” — solar phenomena that had mystified stargazers since antiquity. He writes:
[Unlike] the ordinary Sun-spots … they always appear as if seen through a fog, or veil, between the granulations of the solar surface. On account of their vagueness and ill-defined contours, I have proposed for these objects the term, “Veiled Spots.”
Veiled spots have a shorter duration than the ordinary spots, the smaller types sometimes forming and vanishing in a few minutes. Some of the larger veiled spots, however, remain visible for several days in succession, and show the characteristics of other spots in regard to the arrangement of their parts. The veiled spots have no umbra or penumbra, although they are usually accompanied by faculae resembling those seen near the ordinary spots. They are frequently seen in the polar regions, but are there always of small size and of short duration.
Currently in the public domain, Trouvelot’s exquisite drawings have been generously digitized by the New York Public Library. I have cleaned up, color-corrected, and restored the illustrations to make them available as high-quality prints with proceeds benefiting the endeavor to build New York City’s first public observatory.
Complement Trouvelot’s exquisite marriage of art and science with an abstract contemporary counterpart in artist Lia Halloran’s stunning cyanotypes celebrating women in astronomy.
Published July 7, 2016