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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.
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 Grating module for the Lhires III - 300 l/mm

Shelyak Grating module for the Lhires III - 300 l/mm

by Shelyak
SKU SHK-SE0008
$738.00 - $738.00
$738.00
$738.00 - $738.00
$738.00
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  • Grating for Lhires III Spectroscope
  • 300 lines/mm Ruling
  • Provides Lower Resolution and Wider Spectral Range
  • Complements the Standard 2400 l/mm Grating
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  • Description
  • FAQ
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  • Warranty

  • Grating module for the Lhires III - 300 l/mm

    The Shelyak Grating module for the Lhires III - 300 l/mm is an optional component designed to trade the high resolution of the standard 2400 l/mm grating for significantly broader spectral coverage in a single exposure. This 300 lines/mm grating fundamentally alters the instrument's capabilities, making it suitable for analyzing entire spectral classes of stars or faint, extended objects where capturing the full spectrum is more critical than resolving fine absorption lines.

    From 2400 l/mm to 300 l/mm: Expanding Your Lhires III's Capabilities

    The Shelyak Lhires III spectroscope is supplied with a 2400 lines/mm grating, engineered specifically for high-resolution studies of specific spectral features. This 300 l/mm grating module offers the inverse capability, transforming your specialized instrument into a versatile survey tool.

    By reducing the line count, the 300 l/mm grating disperses light over a smaller angle, allowing a much wider range of wavelengths to fall onto your sensor at once. This trade-off is the core purpose of the module: sacrificing resolving power to gain spectral breadth.

    • Standard 2400 l/mm Grating: Delivers high resolution over a narrow spectral window. It is ideal for measuring the Doppler shift in a binary star's H-alpha line or studying the fine structure of a planetary nebula.
    • Optional 300 l/mm Grating: Provides lower resolution across a very wide spectral window. It is built for capturing the overall spectral energy distribution of an object, classifying a star's type, or monitoring a supernova's evolution across its entire visible spectrum.

    Applications for Low-Resolution Spectroscopy with the 300 l/mm Grating

    With this module, your Lhires III becomes an ideal instrument for spectrophotometry and the study of faint targets. Capturing the spectrum of a dim comet, a distant quasar, or a faint nova becomes feasible, as the lower dispersion concentrates the object's faint light, increasing the signal-to-noise ratio per pixel.

    This grating is also essential for spectral classification. To determine if a star is a hot, blue O-type or a cool, red M-type, you need to see the overall shape of its blackbody curve and the presence of broad absorption features. The 300 l/mm grating allows you to capture this full "fingerprint" in a single frame, making it a powerful tool for stellar astrophysics projects.

  • Why would I choose the 300 l/mm grating for my Lhires III when it comes with a 2400 l/mm grating?

    You would choose the 300 l/mm grating when your scientific goal requires a wide spectral range rather than high resolution. The standard 2400 l/mm grating is for detailed study of narrow spectral lines, while the 300 l/mm grating is for capturing the entire visible spectrum of an object at once, which is necessary for spectral classification or studying objects with broad emission features like novae and quasars.

    What is the main advantage of the 300 l/mm Lhires III grating module?

    The main advantage is spectral coverage. It allows your Lhires III to capture a much wider range of wavelengths in a single exposure compared to the standard high-resolution grating. This makes it possible to analyze the overall energy distribution of a star or capture the full spectrum of faint, extended objects.

    Is the 300 l/mm grating module for the Lhires III good for studying faint objects like comets?

    Yes, it is an excellent choice. Because the 300 l/mm grating has a lower dispersion, it concentrates the faint light from objects like comets, faint novae, or distant galaxies more effectively on your camera's sensor. This results in a higher signal-to-noise ratio, making it easier to obtain a usable spectrum from challenging targets.

    How does the 300 l/mm grating affect the spectrum I can capture with my Lhires III and an 8" SCT?

    With an 8" SCT, the 300 l/mm grating will allow your Lhires III to function as a powerful survey and classification instrument. You will be able to capture the entire visible spectrum of moderately bright stars in a single shot, allowing you to classify them based on their overall spectral features (e.g., O, B, A, F, G, K, M types). This is a task that would be impossible with the narrow-band view of the standard 2400 l/mm grating.

    Can I use the 300 l/mm grating for spectral classification of stars like Vega (Alpha Lyrae)?

    Absolutely. The 300 l/mm grating is perfect for this application. For a star like Vega (Alpha Lyrae), an A0V-class star, this grating will allow you to easily capture the prominent, broad absorption lines of the Balmer series (Hydrogen-alpha, beta, gamma, etc.) that define its spectral type, all within a single image.

    Is swapping the grating in the Lhires III difficult?

    The grating module is designed for user installation, allowing you to switch between resolutions based on your observing targets for the night. While the process is straightforward, it requires care to avoid damaging the optical components. We strongly recommend consulting the official Lhires III user manual for detailed, step-by-step instructions before changing the grating.

  • Grating Ruling 300 lines/mm
    Compatibility Shelyak Lhires III Spectroscope

    • 300 l/mm Grating Module for Lhires III

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  • Shelyak 1-Year Warranty