The Danish 1.54-metre Hβ Photometer

The Danish 1.54-metre Hβ Photometer was mounted on the instrument adaptor at the Cassegrain focus of the Danish 1.54-metre telescope in 1979. This two-channel photometer allowed simultaneous measurements of the Hβ line through a narrow (λHβN = 486.4 nm) and a wide filter (λHβW = 487 nm). By using a neutral-density filter it was also possible to measure bright standard stars fainter than V=4.0 (without the neutral-density filter) or V=1.0 (with the neutral-density filter).

Six diaphragms with different diameters (100, 30, 20, 10, 7 and 4 arcseconds) were available on a wheel that could be rotated by pushing a button on an auxiliary instrument control rack. The data output was saved on paper tape in ASCII.

The Danish 1.54-metre Hβ Photometer was decommissioned in the 1980s.

The Danish 1.54-metre Hβ Photometer

This table lists the global capabilities of the instrument.

Location: Decommissioned
Telescope: Danish 1.54-m telescope
Focus: Cassegrain
Type: Photometer
Wavelength range: 486.4 nm; 487 nm
Spatial resolution:
Spectral resolution:
First light: 1979
Science goal: Stellar photometry
Images taken with the instrument: N/A
Images of the instrument: N/A
Press Releases with the instrument: N/A