Étienne Léopold Trouvelot

Étienne Léopold Trouvelot ( born December 26, 1827 in Guyencourt, Aisne, † April 22, 1895 in Meudon ) was a French astronomer, scientific illustrator and entomologist.

Life

Little is known about the first phase of his life in France. However, he seems to have been involved in politics, because after the coup of Louis Napoleon in 1852, he emigrated to the USA in 1857, where he worked on, among others, with sericulture. His experiments with the resistant against diseases of cultured Antheraea polyphemus by him American style from the kind of peacocks Spinner European style of the gypsy moth ( Lymantria dispar ), however zeitigten fatal consequences. He had imported 1869 eggs of this species for experimental purposes. Unfortunately, some copies escaped and started in the same area of Medford, Massachusetts, where Trouvelot lived with his family at that time to multiply. Trouvelot the danger was aware of it but did not notice his warnings until 1886, the infestation was manifest in the neighborhood. Mid-1890s had spread throughout Massachusetts and since then over considerable parts of North America of the gypsy moth. He meanwhile causes annual losses in the hundreds of millions of dollars.

He became known in the following years as an astronomer and there especially as a gifted observer and creator of high quality astronomical illustrations. The Trouvelot Astronomical Drawings, a series of colored reproductions of his drawings, received wide attention, though not widespread, since the technology produced with chromolithographischer 15 large-format panels ( 965 × 760 mm) with a backing band at the time cost $ 125.

As a member of the Boston Society of Natural History he had first made ​​contributions to entomology, from the early 1870s but turned his interest to astronomy. Through his acquaintance with Joseph Winlock (1826-1875), then director of Harvard College Observatory, he was born in 1872 and received its employees since 1875 access to the 26 " refractor of the United States Naval Observatory, then the largest refracting telescope in the world.

In 1882 he returned to France and joined the staff of Jules Janssen newly established on 1875 in Meudon Observatory. In 1883 he participated in the expedition to observe a total solar eclipse on the part of the Caroline Islands. On this occasion he also tried along with Johann Palisa to locate a hypothetical planet in the solar neighborhood, which could explain the perihelion of Mercury. The search was without result, as are responsible for the path anomaly of Mercury relativistic effects.

Services

Trouvelot authored dozens of articles on astronomy and zoology, and made ​​in the course of his life thousands of astronomical drawings and observational sketches, which belonged to a time when the astronomical photography was still in its infancy at best, especially considering the range of the mapping of the planet was to be had. He used his observations in a grid, which he achieved an accuracy of 6 arc seconds at the reproduced positions of stars. One of his main interests was the sun. Over a thousand of his drawings of sunspots are in the collections of the Harvard College Observatory. 1881 Trouvelot member of the American Academy of Arts and Sciences.

In addition to these services rendered to astronomy he enjoys (especially in the U.S.) the dubious reputation of a man who is directly responsible for the introduction of a pest that destroys every year large areas of forest in the United States. It is the only case that the responsibility for the introduction of an invasive species a single individual can be assigned directly, which is probably not possible, however, Trouvelot would have saved about his accidental release silence.

The lunar crater Trouvelot is named after him.

Works (selection)

• Observations on Jupiter. Boston 1881.
• The Trouvelot Astronomical Drawings. Scribner, New York 1882 - folder with 15 chromo-lithographs
• The Trouvelot Astronomical Drawings Manual. Scribner, New York 1882 - companion volume to folder, digitized
• Observations sur les planètes Vénus et Mercure. Paris 1892.

Partial Lunar Eclipse in 1874

Mars ( Planet)

The " Great Comet " of 1881 ( C/1881 K1)

Group of sunspots