Infrared Spectrometer

NTT IRSPEC instrumentIRSPEC (Infrared Spectrometer) was a multi-purpose spectrometer first installed on the ESO 3.6-metre telescope in the mid-1980s.

Spectrometers collect and separate wavelengths of light to produce what is called a spectra. Spectra can be analysed to learn about the composition, speed, and a number of other characteristics of astronomical objects. IRSPEC gathered near-infrared wavelengths, which allowed astronomers to study gas and dust rich astronomical objects, such as newborn stars.

Cold liquid nitrogen ran throughout IRSPEC to lower the temperature of the optical components to -193ºC and the detector to -223ºC. Heat generated from the instruments running can contaminate the data with heat noise, so cooling instruments can create sharper spectra.

Data taken with IRSPEC was part of a number of studies during the 1980s and 1990s, including the research of comets, supernova, and nebula. In 1994, researchers used IRSPEC to search for molecules  in the impacts of Shoemaker-Levy 9 on Jupiter (eso9402).

After several years on the ESO 3.6-metre telescope, IRSPEC was installed as one of the first instruments on the New Technology Telescope (NTT) in 1989. Developments in infrared technology during the 1990s resulted in more sensitive infrared instruments, and when compared to new technology, the IRSPEC suffered from more noise. In 1997, SOFI (Son of ISSAC) spectrograph therefore replaced IRSPEC on the NTT.


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

ESO 3.6-metre telescope

New Technology Telescope

Type: Infrared Spectrometer
Wavelength range: 1000 – 5000 nm (Infrared)
Spatial resolution:
Spectral resolution: R~1000-2500
First light: November 1985
Science goal: General near-infrared observations
Images taken with the instrument: Link
Images of the instrument: Link
Press Releases with the instrument: Link
  • ESO