The CYCLOPS Concept



The CYCLOPS concept is that of using a small Integral Field Unit (IFU) as an image slicer with an echelle spectrograph. For bright stars observed at high resolution, there is negligible flux present in the sky, so there is no penalty in collecting light from a large area of the sky (several arcseconds) and reformatting it into a long, thin slit at the entrance to an echelle spectrograph.

In this way, if you happen to be at a site with less than optimal seeing, you can collect "all the light at twice the resolution".

There have been two incarnations of CYCLOPS to date.

CYCLOPS2 is as a new-and-improved fibre bundle for CYCLOPS Classic, supplemented by new hardware to mount this bundle on the AAT in the form of the AAO's CURE Cassegrain focus upgrade. CYCLOPS2 has 17 working fibres - 16 that see the sky and a 17th for doing simultaneous wavelength calibration.

It replaces the 5 mirror Coude train, with a Cassegrain-fed optical-fibre bundle, which reformats a ~3" diameter aperture into a pseudo-slit which is 0.63" wide and 15 elements long (or about ~14" on the sky), allowing it to deliver similar throughput to the old mirror train, but with improved spectral resolution (λ/Δλ=70000 compared to 45000 with a 1" slit) and from an aperture equivalent to a 2.45" diameter, which better matches typical AAT seeing conditions than a 1" slit.

CYCLOPS "Classic" - was the first implementation of the CYCLOPS concept, executed as a LIEF-funded upgrade for the Anglo-Australian Telescope's UCLES coude-echelle spectrograph. CYCLOPS Classic was funded and built as a collaborative effort between UNSW, AAO, U.Sydney, ANU and Monash. CYCLOPS Classic had 12 working fibres. As CYCLOPS2 replaces all CYCLOPS Classic's functionality, it is expected to be decommissioned once CYCLOPS2 Commissioning completes.



  1. 4550-7350Å (mid)

  2. NB: Wavelength coverage is complete for λ<5400A. At λ>5400A there are gaps between orders, which grow with wavelength. For example in the 5000-6000A the 79l/mm echellogram coverage is 30% of that obtained with the 31l/mm.


  2. CYCLOPS Classic

  3. CYCLOPS News - with updates from commissioning runs.

  4. CYCLOPS Classic Set-up

  5. CYCLOPS pages at AAO

  6. Instrument availability on AAT

  7. CYCLOPS status page at AAO

  8. AAO UCLES Documentation

  9. Anglo-Australian Planet Search

  10. Exoplanetary Science at UNSW

Page prepared by Chris Tinney,
CYCLOPS Project Scientist.
Last updated 24 April 2013.


The image above shows a section of a ThAr arc spectrum obtained with CYCLOPS2, along with a ThXe spectrum injected through the simultaneous calibration fibre. Each element of the IFU is recorded by UCLES as a single spectrum with spectral FWHM=2.55 pixels.