Zanotti Discovers the Comet of 1739

Zanotti, Eustachio (1709-1782)

La Cometa dell’ anno MDCCXXXIX (1739) osservata nella Specula dell ‚istituto delle Scienze di Bologna nè mesi di Maggio, Giugno, Luglio, e Agosto.

Bologna: nella Stamperia di Lelio dalla Volpe, 1739


Quarto: 26 x 20 cm. With a large folding engraved plate (365 x 500 mm) by Ignatio Bergonzoni: \"Viaggio apparente della cometa osservata in Bologna l‘ anno 1739.\"

Extremely fine, uncut and untrimmed and, consequently, with very broad margins, the large folding plate with one clean tear at the margin, not affecting the image.

First edition, description of the comet of 1739 (C/1739 K1), discovered by Zanotti with his naked eye and observed by him using a telescope at the Bologna Observatory over a period of four months, from 27 May to 17 August 1739. It was the discovery and observation of this comet, which he declared had a parabolic orbit, that first brought Zanotti to the attention of the international scientific community. His calculations of the comet's orbit were published in the Transactions of the Royal Society on 1 January 1740.

"Zanotti described the comet like a star of magnitude 3 but surrounded by nebulosity. Zanotti said his 23-foot focal length telescope revealed a nucleus (probably the central condensation) the size of Jupiter, with a tail extending 2 degrees away from the sun. This tail was said to spread and gradually diffuse as one followed it from its nucleus."(Kronk and Marsden)

Eustachio Zanotti (1709 - 1782), an engineer and astronomer from Bologna, was a pupil of Eustachio Manfredi (1674-1739). Assistant at the Bologna Observatory already at the age of twenty, he became its director at the death of his master, which took place in 1739. One of the most renowned astronomers of his time, Zanotti was a member of numerous Italian and foreign academies, among them the Royal Society of London and the Berlin Academy of Science. A prolific author, he conducted numerous observations on the Sun, the Moon, the planets and the comets. Among his books we may recall one of the first stellar catalogues based on modern principles, dating from 1750, and the three volumes of Bolognese Ephemeris compiled starting from 1751 in collaboration with his assistants Petronio Matteucci and Gabriele Brunelli, as well as numerous studies in mathematics and hydraulic engineering. The 1761 Venus transit was observed in Bologna by Eustachio Zanotti, director of the Observatory, founded in 1726 in the building of newborn Academy of Sciences. The Observatory tower today hosts the Museo della Specola. Zanotti, member of the Academies of Berlin and London, was one of the most known European astronomers of his time. He published a large amount of observations of the Moon, the Sun and the Planets, he edited the Bologna Ephemerides from 1751 to 1764. He was a great hydraulic engineer and in 1778 he became the Secretary of the Istituto delle Scienze di Bologna.

Brüning 1644; Peddie NS, 166b. KVK: only Kiel; COPAC: BL London, Warburg Inst.; OCLC: Adler Planetarium; Univ. Wisconsin; Oklahoma, Huntington.