Dembowski, Ercole

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Dembowski, Ercole

(b. Milan, Italy, 12 December 1812; d. Monte di Albizzate [near Gallarate], Italy, 19 January 1881)


Dembowski was the son of Jan Dembowski, a general of Napoleon, and Matilde Viscontini, an Italian noblewoman. Until he was thirty-one Dembowski was an officer in the Austrian navy; he made several expeditions to the Orient and participated in some minor battles in which he distinguished himself by gallantry.

Having left the navy Dembowski became interested in astronomy. In 1852 he built his own observatory in the village of San Giorgio a Cremano, near Naples, where he made excellent observations of double stars with only a modest telescope of five-inch aperture.

In 1870 he returned to Lombardy and constructed at Monte di Albizzate, near Gallarate, a new observatory equipped with a telescope of seven-inch aperture by Merz and a meridian circle by Starke. With these new instruments he continued the revision of Struve’s Dorpat Catalogue that he had begun in Naples. His energy and perseverance in this work produced an internally consistent series of measurements of the distances and positions of double and multiple stars that extends uninterruptedly over a period of twenty-five years.

Dembowski’s first publication (1857) contains measurements of 127 double and triple stars selected from Struve’s Dorpat Catalogue; each measurement represents the mean of ten observations made on the same night. In 1859 he published a reexamination of all the brightest stars in the Dorpat Catalogue, and in 1860 he listed—with great accuracy—the positions of fifty-four double stars. These measurements were used by Argelander in his fundamental work on proper motion of 250 stars.

Dembowski was a very active observer. He regularly published (mainly in Astronomische Nachrichten) the results of his observations for the benefit of the other astronomers working in the same field.

Following Dembowski’s death Otto Struve credited him with having made about 20,000 observations. At the same time, G. V. Schiaparelli urged the Reale Accademia dei Lincei to undertake the collation and publication of Dembowski’s scattered observations. The work, edited by Schiaparelli and Struve, appeared two years later.

Dembowski was elected an associate member of the Royal Astronomical Society (London) on 8 November 1878 and was awarded the Gold Medal of that society.


I. Original Works. Dembowski’s earliest publication is “Misure micrometriche di 127 stelle doppie e triple di catalogo di Struve,” in Memorie della R. Accademia delle scienze di Napoli, 2 (1855–1857), which was also published in Astronomische Nachrichten; his other observations were published in Astronomische Nachrichten volumes for 1859, 1864, 1866, 1869, 1870, 1872, 1873, 1874, 1875, and 1876; his collected observations are G. V. Schiaparelli and Otto Struve, eds., “Misure micrometriche di stelle doppie e multiple fatte negli anni 1852–1878” in Atti della R. Accademia dei Lincei, 16 and 17 (1883–1884).

II. Secondary Literature. The award to Dembowski of the Gold Medal is noted in Monthly Notices of the Royal Astronomical Society, 38 (1878), 249; see also obituaries in Astronomische Nachrichten (1881) and in Monthly Notices of the Royal Astronomical Society, 42 (1882). 148.

Guglielmo Righini