About us



latest data HSFA2
archive - HSFA 2
prominence archiv HSFA
archive - MFS
flare catalogue
flare catalogue with asymmetry absorption
prominence catalogue 2012
prominence catalogue 2011
Morphological catalog of prominences
Atlas MFS
animated images
Mirror data archi

 Other things

historical page
common life

 Search (Google)


Horizontal-Sonnen-Forschungs-Anlage 2


In 1980s two medium-size horizontal solar telescopes 50/3500 cm with large spectrographs Czerny-Turner made by Carl Zeiss Jena were installed in the Ondřejov observatory. The Czerny-Turner-spectrographs in the Ondřejov 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 forest. 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.

HSFA2 Parameters

1. Feeding Telescope
- Jensh type of coelostat, two mirrors of diameter D = 600 mm
- diameter of the telescope primary mirror DT = 500 mm
- focal lentgh of the telescope primary mirror fmirr = 35 m
- focussing is provided by shifting of auxiliary flat mirror DM = 320 mm
2. Slit-jaw imaging
- slit-jaw image is done with refractor telescope D33mm/F840mm/Feff8543mm
- H-alpha filter DayStar 0.5 A halfwidth is used
- CCD camera VDS Vosskuehler-1300LN
3. Spectrograph
_ metallic slit is open wide
- reflecting mirror with transparent slit 100 mm/100 µm is used
- diameter of the collimator mirror Dcoll = 250 mm
- focal lentgh of the collimator mirror fcoll = 10 m
4. Diffraction grating
- Richardson, Spectra-Physics
- nominal blaze angle - 17.5 deg
- 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
5. Camera objectives
- H-alpha region: mirror 17cm/330 cm, 2 flat mirrors, astigmatism correcting lens
- D3, H-beta, and CaII H (or CaII K) regions: mirrors 15cm/250 cm, and dtto as above
- CaIR 8542 A region: refractor 15cm/160cm
6. CCD Cameras
- 6 pieces of VDS Vosskuehler-1300LN + Grabber Matrix Vision
- size of one pixel 6.7 µm x 6.7 µm
- size of the chip 1280(H) x 1024(V) pixels
7. Typical dispersion curves
- H-alpha region: lambda[A] = 6554.39 (+/- 0.010657648) + npix * 0.0138379 (+/- 1.8622043e-005)
- D3 region: lambda[A] = 5863.21 (+/- 0.007739841) + npix * 0.0193079 (+/- 1.2064653e-005)
- H-beta region: lambda[A] = 4848.41 (+/- 0.010725436) + npix * 0.0207566 (+/- 1.4801976e-005)
- CaII H region: lambda[A] = 3954.91 (+/- 0.0042732762) + npix * 0.0211106 (+/- 5.6048526e-006)
- CaIR 8542 A region: lambda[A] = 8525.73 (+/- 0.010321560) + npix * 0.0281918 (+/- 1.7082068e-005)
- npix = number of pixel [0 .... 1279]

Optical & Electrical Scheme | Manual (Czech) | Install frame-grabber | Software | Gallery | Venus Transit 2004


1. Kotrč P., 2009: The Modernized Horizontal Spectrograph at the Ondřejov Observatory, Cent. Eur. Astrophys. Bull., in print. Full PDF available
2. Kotrč P., 2009: Solar Optical Spectroscopy in the Ondřejov Observatory, Publ. Astron. Obs. Belgrade, in print. Full PDF available
3. Kotrč 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. Full PDF available
4. Klvaňa M., Sobotka M., Kotrč P., Knížek M., Heinzel P., 2001: Reconstruction of the HSFA telescopes, Astronomische Nachrichten, Vol. 322, p. 371-374. Full PDF available
5. Pavel Kotrc, Jurij A. Kuprjakov, Alena Zemanova, Jozef Lesko and Tomas Blaha: 2014; Solar Observations at Ondrejov, 22nd National Solar Physics Meeting, 26 - 30 May 2014, Nizna nad Oravou, Slovakia, Full PDF available
© 2008 Pavel Kotrč, Tomáš Prosecký, Yu. Kupryakov.
Please feel free to send your comments or questions to pkotrc "at-sign" asu.cas.cz or prosecky "at-sign" asu.cas.cz
or jurij.kupriakov"at-sign" asu.cas.cz.