Schönfeld was born at
Hildburghausen, in the Duchy of
Saxe-Meiningen, where he had a distinguished career at the
gymnasium. On leaving the gymnasium, he desired to devote himself to astronomy, but abandoned the idea in deference to his father's wishes. He went first to
Hanover, and afterwards to
Kassel to study
architecture, for which he seems to have had little inclination. 1849 found him studying
chemistry under
Bunsen at
Marburg, where his love for astronomy was revived by
Gerling's lectures. In 1851, he visited the
Bonn Observatory and studied astronomy under
Friedrich Wilhelm Argelander. In 1853, he was appointed assistant, and in the following year won a doctor's degree with his treatise
Nova elementa Thetidis. At Bonn he took an important part in preparing the
Durchmusterung of the northern heavens. He took up the investigation of the light-changes in
variable stars, devoting to this work nights which, on account of
moonlight, were unsuitable for zone observations. The results of these researches were published in the
Sitz. Berich. Wien. Akad. vol. xlii. ==Mannheim Observatory==