Nasmyth Echelle Spectrograph (NES)

The echelle spectrograph NES located at the Nasmyth-2 focus (1:30) platform of the 6-m telescope is a part of the spectral complex ( MSS , LYNX , NES) having a common control.

Development of the echelle spectrograph NES was performed in the framework of the SAO-programme "Modernization of the 6-m telescope". This spectrograph was designed by V.E. Panchuk, V.G. Klochkova, I.D. Najdenov and Prof. N.E. Piskunov (Uppsala University).

Optical elements were produced mainly at the Vavilov Optical Institute and the Optic-Mechanical Corporation, St.Petersbourgh.

This spectrograph provides a spectral resolution R=60000. Its optical layout (without preslit devices) is presented here . The preslit devices are presented here .

The focal length of the collimator is F=7200mm. The diameter of the collimated beam is d=240mm.

The mosaic R2 echelle 600x300mm, 37.5 gr/mm is used in the quasi autocollmation mode.

The gratings for cross dispersion have 300 and 600 gr/mm, the blazed area is 320x360mm.

The Schmidt-Cassegrain camera's focal length is F=600mm, the diameter of the correction plate is D=305mm. Whole camera's optics, including double-pass back alluminated Cassegrain menisc, is made from fused silica.

The diameter of the flat field of this camera is about 40mm.

The first light of the NES was obtained with the CCD 1040x1160 pixels, with the pixel size 16x16mkm. This CCD was developed by the ADL SAO.

In July 2001 the large CCD 2050x2050 producted in Denmark was installed at the NES. The CCD works inside the LINUX environment under the software BIAS developed in Copenhagen University Observatory, Denmark.

We present here some spectra obtained at the 6m telescope using the spectrograph NES in combination with a CCD 2050x2050: high resolution, R=60000, spectrum of subdwarf G27-44 (B=8.0) in the blue spectral range 3500-5000 AA and high resolution, R=60000, spectrum of peculiar star HD4778 obtained in the spectral range 4700-6100 AA with a Zeeman analyzer.

The description of NES (PostScript-file, in Russian) is applied. Besides, some details of the construction and results of a testing are published in the SAO Preprints, 1999, N135, 137 and 138. The results of adaption of a large "Uppsala" CCD 2048x2048 pixels are presented by Panchuk V.E., Piskunov N.E., Klochkova V.G., Yushkin M.V. and Ermakov S.V. in the SAO Preprint N169, 2002 (in Russian). There are positional, photometric parameters of the spectrometer, the parameters of the echelle frame, the sample of observations, etc.

Recent full description of the spectrograph NES is pesented in the paper by V.Panchuk, V.Klochkova, M.Yushkin & I.Najdenov. Journal Optical technology, 2009, v.76, p.87.

In Russian: В.Е.Панчук, В.Г.Клочкова, М.В.Юшкин, И.Д.Найденов, Оптический журн., т.76, с.42 (2009).

A current state of the NES spectrograph is presented in the published paper by V.E.Panchuk, V.G.Klochkova, M.V.Yushkin, Echelle spectrograph gfor the 6-meter telescope BTA. Astron. Rep., v.61, 820-831, 2017.

To consult or request, please, contact with Prof. Vladimir Panchuk:

Here we present some NES-spectra:

The spectrum of the dwarf (F5 V) we derived with the NES
The spectrum of the same dwarf we derived with the BTA+NES in combination with the Jodine cell
The spectrum of the magnetic star HD153882 we derived with the BTA+NES in combination with the Zeeman device
The spectrum of the peculiare born-again Sakurai's object (about 11 mag) we derived with the BTA+NES on July, 15, 1998.

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