Ondrejov Perek 2m Telescope


Latitude:49°54'54.6" North
Longitude:14°46'51.6" East
Altitude:528 m

System - coude

Scheme of the telescope:

Remark: splitting plate (see optical scheme) - glass planparallel plate situated in the tube (inside the hour axis which is also the lighttube) divides environment in coude room and the dome. Thus the plates protects the draught.


  • Mounting: equatorial (special, author Alfred Jensch, Carl Zeiss)
  • Primary mirror: diameter 2m (general diameter 2.08m), thick 30cm, weight 2340kg. Parabolical. Focal ratio 1:4.5
  • Secondary mirror: Diameter 58cm, convex hyperbolical
  • Effective focal length: 63.5m
  • Effective focal ratio: 1:32

  • The 2-metre telescope in Ondrejov has been in operation since 1967, when it was commissioned on the occasion of the XIII General Assembly of the International Astronomical Union (IAU). The construction of the dome began in April 1963. The construction of the 2m telescope started in January 1966 by Zeiss in Jena, and in October 1966, the telescope was transfered to the Astronomical Institute and consequently disassembled and moved in parts to Ondrejov where it was again reassembled. This final assembly was completed in February 1967 and first light through a eyepiece occurred on 8th March 1967. The telescope was officially inaugurated on 23rd August 1967 during the XIII. International Astronomical Union General Assembly. The first spectrum was acquired on 13th October 1967. From the beginning, the telescope was primarily used for spectroscopy. Initially the spectra were first exposed on photographic plates and from 1992 electronic detectors were used. From 1992 to 2000 a Reticon detector was used and since 2000 CCD chips.

    Content, details.

    Our meteostation - Weather monitoring
    Fisheye - Sky monitoring
    Diesel power supply - backup source

    Autoguide - Automatic guiding the telescope
    Coude Spectrograph - short description of the coude spectrograph
    CCD - Technical parameters of our CCD chip
    Files - comments on secured files: zeroes, flat fields, ThAr, stars, darks.
    Reduction - Very short manual for data reduction. FIT headers, IRAF reduction processing, tasks (doslit) etc.
    ThAr atlas - overview of ThAr spectra exposed in Ondrejov.
    S2N ratio - some comments on signal to noise ratio in Ondrejov
    Tricks and tips - IRAF manuals and helps are not very user friendly, so some very basics tips and tricks.
    Examples - some examples of spectra secured in Ondrejov

    Data archive - Virtual Observatory

    Data archive of the Perek Telescope in the Virtual Observatory.