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 Ondejov observatory. The Czerny-Turner-spectrographs in
the Ondejov 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 5C.
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
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
Kotr 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.
Klva?a M., Sobotka M., Kotr P., Knek M., Heinzel P.:
Reconstruction of the HSFA telescopes, Astronomische Nachrichten,
Vol. 322, p. 371-374., 2001
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.