When Tartu University received the Fraunhofer refractor, the dome was rebuilt according to Parrot’s design. Its construction, which was also described in publications, turned out to be so successful that it was applied in many new observatories (Helsinki, Pulkovo, and others following their example). In 1859 the gallery round the tower was renewed after the design of the architect Karl Rathaus.

The reconstruction design of the tower made under the supervision of professor G. F. Parrot (Beschreibung des auf der Sternwarte der Kaiserlichen Universität zu Dorpat befindlichen grossen Refractors von Fraunhofer. Herausgegeben von F. G. W. Struve, Director der Sternwarte. Dorpat: Schünmann, 1825).
The cross-section of the observatory, 1827 (Die Kaiserliche Universität zu Dorpat: fünfundzwanzig Jahre nach ihrer Gründung: Dorpat MDCCCXXVII. Hrsg. J. P. G. Ewers. Dorpat, Schünmann, 1827).

For new instruments the old observatory did not have sufficient space and in the second half of the 19th century step by step an astronomical park was formed: in the 1860s in the north-east an additional pavilion was erected for locating the Repsold heliometer in 1873, in 1889 a wooden pavilion to the south-east of the observatory was built with hatches in the meridian and the first vertical.

In 1895 bigger repairs were carried out in the course of which electricity was installed (for illumination and for electrical clocks). In the north-western edge of the hill a cylindrical tower with the rotating roof was built for the zenith-telescope, later there was the Petzval astrograph.

The complex of the observatory, 1902 (TÜR. Album 1. P. 8)

During World War 1 and World War 2 the building of the observatory did not suffer from destruction. In 1933 water mains were installed and in 1934 the photography laboratory was taken from the cellar to Struve’s house. After World War 2 the Tartu observatory was transferred from Tartu University and subordinated to the Academy of Sciences. To get new space, in 1950/52 a separating ceiling was built in the western hall. On the lower floor there was the library, on the upper floor the theoretical physicists had their rooms. In the neighboring astronomer’s house the sector of experimental physics (the laboratory of luminescence and the study of crystals headed by F. Klement which in 1959 was awarded with the research prize of the Estonian SSR) began to work and in the attic there were accountants.

Physicists before the observatory

When observation activities began at Tõravere instead of Tartu, the old Tartu observatory housed a branch of the City Museum of Tartu in 1975-1996.

Hugo Raudsaar with the members of the astronomy club at the observatory, 1983 (EFA. 0-134633)

On 24 February 1989 in the observatory tower, the highest point in the centre of Tartu, the Estonian state flag – blue-black-and-white - was openly hoisted for the first time.

In 1996 the Tartu observatory building was returned to the University of Tartu, the former museum finished its activities and the building became the home for the AHHAA science centre. In 1992 the first Internet connection in Tartu was installed in the observatory building. In the old observatory the EENet – the Estonian Educational and Research Network (the server was there up to the spring of 2009) and the Estonian Biocentre started their work.

In 2009-2010 the western hall was restored in the original shape, i.e. the partitioning ceiling was removed, the whole building and the astronomer’s house were renovated. In 2011 the Museum will start its work.

Tartu Observatory 21.11.2008