SCORPIO=Spectral Camera with Optical Reducer for Photometrical and Interferometrical Observations
SCORPIO is a multi-mode focal reducer of the BTA. It it used for observations of star-like and extended objects in following observational modes at the prime focus (F/4) of the 6m telescope:
  • Broad-, medium- and narrow band direct imaging
  • 2D spectroscopy with the scanning Interferometer Fabry-Perot*
  • Long-slit spectroscopy
  • Spectropolarimetry (Right now we lack of phase plate. If you want to observe circular polarization in this mode, please, contanct me at
  • Slitless spectroscopy
  • Multi-slit spectroscopy with 16 movable slits

The device consists of the Focal Reducer (F/2.6) and of the prime focus Adapter (with tip-tilt auto-guiding system and lamps for flat-field and wavelength calibrations).
* Until 2013. Now FPI mode is working at the SCORPIO-2.
Please read new version of SCORPIO User manual (Jan 2013): Russian PDF

If your paper based on SCORPIO observations, we would appreciate the following citation of the main paper with description of the device: Afanasiev V.L. & Moiseev A.V., 2005, PaZh, 31, 214 (Russian PDF); English translation: 2005, Astronomy Letters, 31, 194 ( English PDF ).
Thank you!

SCORPIO design:

The optical part contains of the collimator (F/2.2) and the camera (F/1.8). The total focal ratio it the prime focus of the telescope is (F/2.6). The optics of the reducer compensate for the aberrations of the main mirror of the telescope, all optical surfaces have antireflecting coating in a spectral range 3500-10000 A. SCORPIO has two filter's wheels for interferometric narrow-band and middle-band filters (Wheel 1 in the focal plane) and for broad-band filters (Wheel 2 between the field lens and the collimator). The dispersers (grisms or Queensgate IFPs ET-50) installed between the collimator and the camera where the exit pupil of the optical system is located. The diameter of the collimated beam is 35mm.

The first light on 6m telescope was taken 21 September 2000. The similar device (without adapter) was constructed by us for 2.6m telescope in the Byurakan (Armenia).
SCORPIO contact astronomer: Gabdeev M.M. (

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