It is located in Babelsberg in the state of Brandenburg, just west of Berlin, though the Einstein Tower solar observatory and the great refractor telescope[1] on Telegrafenberg in Potsdam belong to the AIP.

Initiated by Gottfried W. Leibniz, on July 11, 1700 the "Brandenburgische Societät" (later called the Prussian Academy of Sciences) was founded by the elector Friedrich III in Berlin.

This happened in a hurry, because the profits from the national basic calendar, calculated and sold by the observatory, should have been the financial source for the academy.

The discoveries of the canal rays by Eugen Goldstein in 1886 in the physical laboratory of the observatory and of the variation in the altitude of the Earth's pole by Karl Friedrich Küstner in 1888 were likewise important.

The site of the observatory was chosen on a hill south of Potsdam, the Telegrafenberg, on which had been, from 1832 to 1848, a relay station of the military telegraph from Berlin to Koblenz.

Even before the construction of the observatory had started in the autumn of 1876, solar observations were being made from the tower of the former military orphanage in Linden Street in Potsdam by Gustav Spörer.

The AOP was managed by a board of directors comprising Wilhelm Julius Foerster, Gustav Kirchhoff and Arthur Auwers.

Although it did not realize all the hopes astronomers had for it, nevertheless two important discoveries should be mentioned: the interstellar calcium lines in the spectrum of the spectroscopic binary Delta Orionis by Johannes Hartmann in 1904[3] and the presence of stellar calcium emission lines — a hint of stellar surface activity — by Gustav Eberhard and Hans Ludendorff about 1900.

In only a few years of work (by 1916 he had died from a chronic illness) he had made fundamental contributions in astrophysics and to General Relativity Theory.

In 1881 Albert A. Michelson first performed his interferometer experiments[4] in the cellar of the main building of the AOP, that were to disprove the movement of the Earth through a hypothetical aether.

To prove the gravitational redshift of spectral lines of the Sun — an effect proposed by Einstein's theory of General Relativity — was the aim of a solar tower telescope, which was built from 1921 to 1924 at the instigation of Erwin Finlay-Freundlich.

Though at that time it was not yet technically possible to measure the gravitational redshift, important developments in solar and plasma physics were started here and the architect, Erich Mendelsohn, created with this peculiarly expressionistic tower a unique scientific building.

Besides the work of Schwarzschild, in the following decades important observational programmes such as the Potsdamer Photometrische Durchmusterung and the outstanding investigations of Walter Grotrian on the solar corona found recognition all over the world.

At the end of the 19th century the Berlin Observatory, originally built outside the border of the town, was enclosed by blocks of flats, so scientific observations were almost impossible.

After test observations by Paul Guthnick in the summer of 1906 a new site was found on a hill in the eastern part of the Royal Park of Babelsberg.

The costs of the new buildings and the new instruments amounted to 1.5 million Goldmark and could be covered by selling the landed property of the Berlin Observatory.

Struve died in 1920 from an accident, and his successor was Paul Guthnick, who introduced in 1913 photoelectric photometry into astronomy as the first objective method of measuring the brightness of stars.

In Potsdam the Einstein Tower had suffered heavy damage by bombs, in Babelsberg valuable instruments, among them the 122 cm telescope (whose former building now houses the AIP library), were dismounted and removed to the Soviet Union as war reparations.

In January 1947 the German Academy of Sciences took the AOP and the Babelsberg Observatory under its administration, but it was not until the beginning of the 1950s before astronomical research started anew.

In June 1954 the Observatory for Solar Radio Astronomy[7] (OSRA) in Tremsdorf (17 km southeast of Potsdam) began its work as a part of the AOP.

After the Second World War Herbert Daene started once again to attempt radio observations of the Sun in Babelsberg which were continued in Tremsdorf.

On the basis of the prescriptions of the Unification Agreement for the Academy of Sciences of the GDR, the Central Institute of Astrophysics was dissolved on 31 December 1991.

With their 110 square meter area, the LBT is the largest telescope in the world on a single mount, only surpassed by the combined VLTs and Kecks.

The AIP is involved in the operations and scientific exploitation of two instruments: the Spectrometer Telescope for Imaging X-rays (STIX), and the Energetic Particle Detector (EPD).

The investigation of these small structures is important for the understanding of the underlying processes of the interaction of magnetic fields with plasma turbulence on the Sun.

The AIP is a partner in the LBT Consortium (LBTC) and contributes financially and materially in the construction of the Large Binocular Telescope.

4MOST[16] is a multi-fiber, multi-spectrograph instrument that shall replace VIRCAM at the 4 m VISTA (telescope) and perform a 5-year survey of both galactic and extra-galactic targets.