• FA-103194_Brahe-Sextant © Technisches Museum Wien, Photo: Peter Sedlaczek
Collection Area
Technical and Scientific Principles
Physical/Chemical Fundamentals
At the moment this object is not published in the museum.



Sextants are devices for measuring angles. They are used to determine the position of stars and (as small, manual devices) for determining one's position at sea.

The name "sextant" refers to its shape as one sixth of a full circlular disk. The large sextant from the collection of the Technisches Museum Wien (Vienna Technical Museum) is a copy of the instrument built in 1582 by the astronomer Tycho Brahe. With a radius of 1.6 metres, the devices were so heavy that they were later fixed to walls.

Bearings were taken on stars or planets using the sighting facility. The angle to the horizon or to another celestial body was read from the large angle scale attached to the edge. Together with the time at which the reading was taken, this provided two coordinates that clearly gave the position of the celestial body. A short time later, Johannes Kepler was able to prove the rules for the movements of the planets using these coordinates.

For centuries, the angle and time were the most important sources of data for “observational astronomy”, particularly celestial mechanics.

Manufacturer: University of Oldenburg
Date of construction: 1998

Inv.Nr. 50149/1
Member of