Spectrograph HSFA2

Description and Technical Details

In 1980s two medium-size horizontal solar telescopes 50/35000 cm with large spectrographs Czerny-Turner made by Carl Zeiss Jena were installed in the Ondøejov observatory. The Czerny-Turner-spectrographs in the Ondøejov observatory called HSFA1 and HSFA2 according to the German name Horizontal-Sonnen-Forschungs-Anlage ("horizontal device for solar research") have been explored for more than two decades. A process of modernization was completed recently. The reconstruction of the optical parts of the spectrograph of the HSFA2, which is supposed to be overbuilded into a multichannel spectrograph operating simultaneously in several diagnostically important spectral lines, is decribed briefly.

The high quality equipment of the HSFA2 was made by Carl Zeiss, Jena. There is a better resolution (angular resolution is 0.33" for H-alpha, the chromatic resolution is 12.60 mA for H-alpha) and high quality optics. The HSFA2 is placed about 400m far away from the main building in a forrest. There are no streets and buildings in the neighbourhood of the spectrograph room or other unwanted source of air-convection. The height of the coelestat above the ground is about 6 m. But there are several disadvantages. The HSFA2 is more complicated to activate due to the installed hydraulic system which is usable only by temperature above 5°C. Other problem was that the original grating and objective were dedicated for configurations of larger detectors. But the main problem was the fact that we had a limited space inside the spectrograph-room. The long and narrow room was designed for a one-way-spectrograph.

Parameters HSFA2

  1. diameter of the telescope primary mirror DT=500 mm

    - focal lentgh of the telescope primary mirror fmirr=35 m

    - focal lentgh of the collimator mirror fcoll=10 m

  2. Diffraction grating - Richardson, Spectra-Physics

    - nominal blaze angle - 17.5

    - nominal wavelengh 1st order (Littrow) - 500 nm

    - the width of the diffraction grating W=206 mm

    - the height of the diffraction grating H=154 mm

    - number of grooves per mm - 1200

    Camera - VDS Vosskuehler: CCD-1300LN

    - size of one pixel 6.7 μm x 6.7 μm

    - size of the chip 1280(H) x 1024(V) pixels

·Optical scheme· ·Electtrical scheme· ·Manual HSFA2· ·Install frame-grabber ·Images HSFA-2·



  1. Kotrè P., Kschioneck K.: 2003; From Czerny-Turner to a Multichannel Spectrograph, from Photografic to CCD Detectors ; in Proc. of the International Solar Cycle Studies 2003 Symposium: "SOLAR VARIABILITY AS AN INPUT TO THE EARTH`S ENVIRONMENT", held June 23-28, 2003, Tatranska Lomnica, Slovak Republic, ESA SP-535, A. Wilson (ed.), p. 717-722.
  2. Klvaòa M., Sobotka M., Kotrè P., Knížek M., Heinzel P.: Reconstruction of the HSFA telescopes, Astronomische Nachrichten, Vol. 322, p. 371-374., 2001
  3. Kotrc P., Kupryakov Yu. A., J. Lesko: 2006; Modernizovany opticky spektrograf v Ondrejove - popis, data, zkusenosti, vyhledy; Zbornik referatov z 18. celostatneho slnecneho seminara, Modra, cerven 2006, editor I. Dorotovic, SUH Hurbanovo, publikovano na CD prispevek c. 31.
  4. P. Kotrc, E. V. Kononovich, Yu. A. Kupryakov:2007; Solar spectral observations at the Ondrejov Observatory with Moscow State University cooperation ; Astronomical and Astrophysical Transactions Vol. 26, Nos. 4-5, August-October 2007, 267-273.