Bochum Photometer

The Bochum Photometer was installed at the Cassegrain focus of the Bochum 0.61-metre telescope at La Silla Observatory in 1968. This photoelectric stellar photometer was designed by J. Dachs and built by the Zentralwerkstatt Göttingen GmbH, in Göttingen, Germany. The instrument was owned by the German Research Foundation and was given on permanent loan to the Astronomical Institute of the Ruhr University in Bochum, Germany.

The Bochum Photometer was composed of different parts that could be easily inserted and exchanged. Sixteen different filters, two lenses and different photomultipliers were available to it. The installation of an HP 2114B computer with 8K for the computer control system of the telescope and the photometer in 1971 greatly improved data acquisition with the Bochum 0.61-metre telescope.

The Bochum Photometer was used in many photometric studies of luminous OB stars and supergiants in southern open clusters, selected Milky Way fields and the Magellanic Clouds. The lowest magnitude observable by the system was 15.5.

The Bochum Photometer is decommissioned.

Bochum Photometer at the Bochum 0.61-metre telescope

This table lists the global capabilities of the instrument.

Location: Decommissioned
Telescope: Bochum 0.61-metre telescope
Focus: Cassegrain
Type: Photometer
Wavelength coverage:

411.8–656.6 nm

Spatial resolution:  
Spectral resolution: 0.27–23 nm
First light date: 7 September 1968
Science goals:
  • Photometric studies of luminous OB stars and supergiants
Images taken with the instrument: N/A
Images of the instrument: Link
Press Releases with the instrument: N/A


  • German Research Foundation
  • Astronomisches Institut der Ruhr-Universität Bochum
  • ESO