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.
- diameter of the telescope primary mirror
- focal lentgh of the telescope primary mirror
- focal lentgh of the collimator mirror fcoll=10 m
- 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
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
- 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.
- Klvaòa M., Sobotka M., Kotrè P., Kníek M., Heinzel P.:
Reconstruction of the HSFA telescopes, Astronomische Nachrichten,
Vol. 322, p. 371-374., 2001
- 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.
- 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.