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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Shelyak eShel III Complete System

Shelyak eShel III Complete System

by Shelyak
SKU SHK-ES0006
$22,499.00 - $22,499.00
$22,499.00
$22,499.00 - $22,499.00
$22,499.00
Price Match Policy!
  • Professional echelle spectrograph system
  • Resolving power of R > 10,000
  • Covers 390nm to 700nm spectral range
  • Fiber-optic fed for maximum stability
  • Includes FIGU, calibration module, and fibers
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Shelyak eShel III Complete System

    The Shelyak eShel III is a complete, professional-level fiber-optic echelle spectrograph system, delivering a resolving power of R > 10,000 across a wide 390nm to 700nm spectral range. It achieves this by capturing diffraction orders 32 through 53 simultaneously, using a 50µm fiber for the target and a 200µm fiber for calibration to ensure maximum stability for demanding applications like exoplanet radial velocity studies.

    This instrument is designed for observers who cannot compromise between spectral range and resolution. Developed from experience with professional spectroscopes like Musicos and Narval, the eShel III provides a turnkey solution for advanced astrophysical research. Please note, this system is available by quote only.

    R>10,000 Resolution Across the Visible Spectrum (390-700nm)

    The core of the eShel III is an echelle grating that uses over 30 diffraction orders to achieve high resolution. A cross-disperser then stacks these orders across the camera sensor, allowing you to capture the entire visible spectrum from 390nm to 700nm in a single exposure. This multi-order spectrum provides comprehensive data, ideal for monitoring variable stars or classifying stellar objects without sacrificing detail.

    Thermally Stable Radial Velocity with a Fiber-Fed Design

    Precision in spectroscopy, especially for exoplanet detection, requires extreme stability. The eShel III uses a 20-meter-long optical fiber to physically separate the spectrograph from the telescope, allowing the instrument to be placed in a temperature-controlled environment. This isolation from thermal fluctuations and mechanical vibrations at the telescope is critical for accurate radial velocity measurements.

    The complete system includes the F/6 Fiber Injection and Guiding Unit (FIGU) for precise starlight injection into the 50µm object fiber, and a dedicated calibration module with a Thorium-Argon (ThAr) lamp. The calibration spectrum is fed through a separate 200µm fiber, providing a stable reference for sub-pixel velocity measurements.

    Integrated Control: Remote Acquisition and Data Reduction Software

    The eShel III system includes Demetra, a powerful and free software suite for MS Windows that manages the entire observation workflow. From the control room, you can remotely operate the FIGU and the calibration module, automate image acquisition, and process the complex echelle spectra. The software handles the extraction and calibration of the multiple orders, converting raw images into scientifically useful data, streamlining what would otherwise be a complex data reduction process.

  • What is the primary advantage of the eShel III's echelle design?

    The echelle design solves the classic trade-off in spectroscopy. It delivers both high resolution (R > 10,000) and a wide spectral range (390-700nm) simultaneously. This is impossible with a traditional single-order spectrograph, making the eShel III ideal for comprehensive studies of stellar atmospheres, variable stars, and exoplanet transits.

    Why does the eShel III system use optical fibers?

    The optical fibers are crucial for achieving the high stability required for precise radial velocity measurements. By physically separating the spectrograph from the telescope with a 20-meter fiber, the instrument can be kept in a thermally stable room, isolated from temperature changes and vibrations that would otherwise compromise the data. This is a standard technique in professional observatories.

    What components are included in the eShel III complete system?

    The eShel III is sold as a complete, integrated solution. The package includes:

    • The eShel spectroscope main module
    • The F/6 Fiber Injection & Guiding Unit (FIGU)
    • The calibration module with a Thorium-Argon (ThAr) lamp
    • A 20m, 50µm optical fiber for the target star
    • A 20m, 200µm optical fiber for the calibration lamp

    You will need to provide a suitable astronomical camera and telescope.

    What kind of camera do I need for the eShel III?

    The eShel III does not include a camera. The choice of camera depends on your research goals, but it requires a sensor large enough to capture the full array of stacked spectral orders. A camera like the ATIK 460EX Monochrome is often recommended, as its sensor size and pixel characteristics are well-matched to the instrument's output when used in 2x2 binning mode.

    How would I use the eShel III to study the radial velocity of a star like 51 Pegasi?

    To measure the subtle Doppler shift caused by an exoplanet, you would use the fiber-fed system to ensure thermal stability. You would acquire a long series of spectra of 51 Pegasi, taking a calibration spectrum with the internal ThAr lamp before and after each observation. The R > 10,000 resolution is high enough to detect the small wavelength shifts, and the Demetra software would be used to precisely measure these shifts against the stable ThAr reference lines, revealing the gravitational "wobble" induced by its planet.

    Can the eShel III capture the spectrum of a pulsating star like BW Vulpeculae in a single exposure?

    Yes, this is an ideal application for the eShel III. Its ability to capture the entire 390-700nm spectrum at high resolution in one shot allows you to monitor changes in spectral lines across the star's atmosphere simultaneously. For a rapidly pulsating star like BW Vulpeculae, taking a series of 5-minute exposures would allow you to build a time-series dataset to analyze the atmospheric dynamics throughout its pulsation cycle.

  • Instrument Type Multi-order Echelle Spectrograph
    Resolving Power R > 10,000
    Spectral Range 390 nm - 700 nm
    Diffraction Orders 32 to 53
    Input Connection Fiber-optic (FC/PC connector)
    Object Fiber 50µm diameter, 20m length
    Calibration Fiber 200µm diameter, 20m length
    Included Modules F/6 Fiber Injection & Guiding Unit (FIGU), Calibration Module
    Calibration Source Thorium-Argon (ThAr) Lamp
    Control Software Demetra (MS Windows)

    • eShel Spectroscope Main Module

      × 1

    • F/6 Fiber Injection & Guiding Unit (FIGU)

      × 1

    • Calibration Module with ThAr Lamp

      × 1

    • 50µm Target Optical Fiber

      × 1 (20m length)

    • 200µm Calibration Optical Fiber

      × 1 (20m length)

  • Shelyak 1-Year Warranty