In the same time, light pollution from the surrounding city as well as vibrations caused by the still increasing traffic in the streets below had made the observations inaccurate.

The well-known Russian-German astronomer, Heinrich Louis d'Arrest, who had been appointed professor in astronomy at the university in 1857, was chosen to plan the new observatory.

He also did significant work in spectroscopy, and discovered, for the first time, the differences in the evolutionary state and spatial distribution of stars.

[1] The next director of the Østervold Observatory was Thorvald N. Thiele, a skilful mathematician who developed a new method of determining the orbit of Binary stars.

[2] In 1907, Elis Strömgren was appointed professor and director of the observatory, and under his direction the computational work continued.

During World War I, the Central Bureau for Astronomical Telegrams, founded by Astronomische Gesellschaft in 1882, was moved from Kiel, Germany, to the Østervold Observatory.