Nils Dunér 1890-tal
Nils Dunér in the observatory, 1890s

During the 19th century, astronomy was transformed by technological developments. The Universe opened up to science at the same rate as new and ever more precise ways of making observations were discovered. Astronomers now realised how infinitely large the Universe is and they attempted to understand how stars are created.

In the 18th century, astronomical observations were used to determine time and location, to enable clocks to be set and maps to be drawn. But advances in technology during the 19th century pushed astronomy into a new period of development. The focus moved from calculating the time and making maps of the heavens to studies of the physics of the stars, their origin and composition – and, thus, towards an understanding of the whole Universe.

The spectrometer gave birth to astrophysics

determine the positions and movements of the stars. This knowledge made it possible to determine the distances to the nearest stars, revealing how incredibly large and empty the Universe is.
Optical spectroscopy, the analysis of light spectra, now made its entry into astronomy. All new telescopes were equipped with spectrometers. The ability to study and analyse the light from stars paved the way for a completely new field in astronomy – astrophysics. Using spectroscopy, astronomers could now find out about the composition and physical characteristics of stars.

Photographs made astronomy objective

Developments in photography during the second half of the 19th century also drove astronomy forwards. Photography became an important tool for the study of stars and the Universe. The camera made it possible to measure the position and brightness of stars objectively, without the results being affected by the observer’s own perceptions. Many of the early photographs of space still remain at observatories and are sometimes used to study how stars have changed over time.