Donati, Giovanni Battista
Giovanni Battista Donati (jōvän´nē bät-tēs´tä dōnä´tē), 1826–73, Italian astronomer, b. Pisa. Serving as director of the Florence Observatory from 1864, he was a pioneer in the spectroscopic study of the stars and the sun. Donati was the first to obtain and analyze the spectrum of a comet, concluding that the composition of comets is, at least in part, gaseous. He discovered (1854–64) six new comets, among them Donati's comet, which he first saw on June 2, 1858.