Sheklyak Eshel

Eshel is your complete and fully operational spectroscopy solution specially designed for astronomy. This unique and highly performing instrument will allow you to productively run your spectroscopic observations.

* F/6 - 50m - fibre injection & guiding unit
* object optical fibre 50m, protected by inox
* echelle spectrograph F/5; R >10000
* calibration unit controled by computer
* calibration fibre 200m, protected by inox
* software module for AudeLA (Tcl/Tk)

We designed the spectrograph with Christian Buil, a higly recognized optician expert. The software module has been written by Michel Pujol, an expert in Tcl/Tk and AudeLA platform. They both complement our expertise to bring you the best solution in echelle spectroscopy for astronomy!

Choice of optical fibre has been made to increase radial velocities measurement accuracy and for a better confort in using the eShel.

The complete solution is made of four major modules:

Fiber Injection & Guiding Unit
* M42 T-adapter telescope interface
* Backfocus 43mm
* Miror with light going through a 50m hole for the f/6 standard version (a 75m f/9 version exists - contact us for details)
* Calibration fiber input (remote controlled mirror position)
* Fibre optics
o 50m object fiber
o 200m calibration fiber
o fibers protected by metal/plastic casing
o FC fiber connectors
* Guiding camera (C-mount; video Watec 120N+ recommended)

Calibration Unit
* Thorium-Argon lamp with high voltage power supply for precise calibration
* Flat lamp for echelle order geometry and blaze processing
* Electronic to control remotely calibration frame acquisition

echelle spectrograph
* Cross-dispersed echelle spectrograph
o f=125mm collimator (f/5)
o R2 high efficiency echelle grating
o coated prism cross-disperser
o 85mm f/1.8 objective
* Compact
* High power of resolution R=10000
* Visible domain (around 450-700nm)
* Optimized for large telescope (50m fiber)
* Choice of imaging camera
o KAF1603me chip based (size >13*9mm)
o QSI 516ws or SBIG ST1603me camera recommended
o Canon EOS lens interface with standard SLR backfocus
eShel Software
* Easy to use
* Open source, based on AudeLA platform and Tcl/Tk language
* work on MS Windows platform
* multi-language support
* Remote-controlled operations
* Automatic spectra reduction procedure after acquisition
* FITS file support with multiple HDU
* Export individual orders or merged spectrum
* Download here an exemple of a processed echelle spectrum of our Sun (open with multi-HDU FITS reader such as fitsview).