The 3.6-m Infrared Photometer/Spectrophotometer

The 3.6-m Infrared Photometer/Spectrophotometer was mounted at the F/35 focus of the ESO 3.6-metre telescope at La Silla Observatory in 1980. The infrared photometer project was started at ESO (Geneva) by Piero Salinari, in 1978.

The 3.6-m Infrared Photometer/Spectrophotometer consisted of a photometer mount and two detector units, one for the 1000–5000 nm region and the other for the 2000–25000 nm region. The detectors were equipped with 18 broad and intermediate-width filters that covered the 1500–5500 nm and 8000–14000 nm regions.

Between 1980 and April 1982 the 3.6-m Infrared Photometer/Spectrophotometer was used to observe stellar occultations by the Uranus system, that allowed astronomers to learn more about the known rings and to find new ones. In combination with optical photometry and X-ray observations it was used to investigate the stellar types of X-ray source companions and the nature of the emission from the black-hole candidate GX 339-4.

Data acquisition and control of the detectors was performed with two separate HP 2645 terminals using an Infra-Red Acquisition (IRA) program.

The 3.6-m Infrared Photometer/Spectrophotometer is now decommissioned.

The 3.6-m Standard Photometer

This table lists the global capabilities of the instrument. The authoritative technical specifications as offered for astronomical observations are available from the Science Operations page.

Location: Decommissioned
Telescope: ESO 3.6-m telescope
Focus: F/35
Type: Photometer/Spectrophotometer
Wavelength range:

1500–5500 nm

8000–14000 nm

Spatial resolution:


Spectral resolution: ~70
First light: October 1980
Science goal:
  • Photometry
  • Spectrophotometry
  • Mapping
  • Speckle observations
Images taken with the instrument: N/A
Images of the instrument: Link
Press Releases with the instrument: N/A
  • ESO